Each of the 31 qualifiers for the 2018 World Cup, plus the hosts, have named their provisional 35-man squads for the tournament in Russia and now have until June 4 to cull the numbers down to 23.
Some, like England and Brazil, have already named their final 23-man squads.
Those who do not make the cut are placed on standby in case they are needed to replace any injured players.
Replacements can be made at any point until 24 hours before each team's first World Cup game.
Here is what we know so far about each squad:
Group A
Egypt
29-man preliminary squad: Essam El Hadary, Mohamed El-Shennawy, Sherif Ekramy, Mohamed Awad; Ahmed Fathi, Saad Samir, Ayman Ashraf, Mahmoud Hamdy, Mohamed Abdel-Shafy, Ahmed Hegazi and Ali Gabr, Ahmed Elmohamady, Karim Hafez, Omar Gaber, Amro Tarek; Tarek Hamed, Mahmoud Abdel Aziz, Shikabala, Abdallah Said, Sam Morsy, Mohamed Elneny, Kahraba, Ramadan Sobhi, Trezeguet, Amr Warda; Marwan Mohsen, Ahmed Gomaa, Kouka, Mohamed Salah
Russia
28-man preliminary squad: Igor Akinfeev, Vladimir Gabulov, Soslan Dzhanaev, Andrey Lunev; Vladimir Granat, Sergei Ignashevich, Fedor Kudryashov, Ilya Kutepov, Roman Neustadter, Konstantin Rausch, Andrey Semenov, Igor Smolnikov, Mario Fernandes; Yuri Gazinskiy, Alexsandr Golovin, Alan Dzagoev, Alexsandr Erokhin, Yuri Zhirkov, Daler Kuzyaev , Roman Zobnin, Alexsandr Samedov, Anton Miranchuk, Alexsandr Tashaev, Denis Cheryshev; Artem Dzyuba, Aleksey Miranchuk, Fedor Smolov, Fedor Chalov.
Saudi Arabia
26-man preliminary squad: Assaf Al-Karny, Mohamed Al-Owais, Yasser Al-Musailem, Abdullah Al-Mayuf, Mansour Al-Harby, Yasser Al-Shahrany, Mohamed Al-Breik, Said Al-Muwalad, Motaz Hawsawi, Ossam Hawsawi, Omar Hawsawi, Mohamed Jahfali, Ali Al-Buhaili, Abdallah Al-Khaibari, Abdelmarek Al-Khaibari, Abdallah Otayf, Taiseer Al-Jassem, Hussein Al-Mafhawy, Soliman Al-Faraj, Nawaf Al-Abd, Mohamed Kano, Hattan Bahbary, Mohamed Al-Kowaikaby, Salem Al-Dawsari, Yehia Al-Shahry, Fahd Al-Muwalad, Mohamed Al-Sahlawy, Muhannad Asiri
Uruguay
26-man preliminary squad: Fernando Muslera, Martin Silva, Martin Campana, Diego Godin, Sebastian Coates, Jose Maria Gimenez, Maximiliano Pereira, Gaston Silva, Martin Caceres, Guillermo Varela, Nahitan Nandez, Lucas Torreira, Matias Vecino, Federico Valverde, Rodrigo Bentancur, Carlos Sanchez, Giorgian De Arrascaeta, Diego Laxalt, Cristian Rodriguez, Jonathan Urretaviscaya, Nicolas Lodeiro, Gaston Ramirez, Cristhian Stuani, Maximiliano Gomez, Edinson Cavani, Luis Suarez
Group B
Iran
35-man preliminary squad: Alireza Beiranvand, Seyed Hossein Hosseini, Rashid Mazaheri, Amir Abedzadeh; Ramin Rezaeian, Voria Ghafouri, Steven Beitashour, Seyed Jalal Hosseini, Mohammad Reza Khanzadeh, Morteza Pouraliganji, Mohammad Ansari, Pejman Montazeri, Seyed Majid Hosseini, Milad Mohammadi, Omid Norafkan, Saeid AGhaei, Roozbeh Cheshmi; Saeid Ezatolahi, Masoud Shojaei, Ahmad Abdolahzadeh, Saman Ghoddos, Mahdi Torabi, Ashkan Dejagah, Omid Ebrahimi, Ehsan Hajsafi, Ali Karimi, Soroush Rafiei, Ali Gholizadeh, Vahid Amiri; Alireza Jahanbakhsh, Karim Ansarifard, Mahdi Taremi, Sardar Azmoun, Reza Ghoochannejhad, Kaveh Rezaei
23-man final squad: Yassine Bounou, Mounir El Kajoui, Ahmad Reda Tagnaouti, Badr Banoun, Mehdi Benatia, Manuel da Costa, Nabil Dirar, Achraf Hakimi, Hamza Mendyl, Romain Saiss, Youssef Ait-Bennasser, Sofyan Amrabat, Nordin Amrabat, Younes Belhanda, Mbark Boussoufa, Karim El Ahmadi, Faycal Fajr, Amine Harit, Hakim Ziyech, Aziz Bouhaddouz, Khalid Boutaib, Mehdi Carcela, Ayoub El Kaabi
23-man final squad: Anthony Lopes, Beto, Rui Patricio, Bruno Alves, Cedric Soares, Jose Fonte, Mario Rui, Pepe, Raphael Guerreiro, Ricardo Pereira, Ruben Dias, Adrien Silva, Bruno Fernandes, Joao Mario, Joao Moutinho, Manuel Fernandes, William Carvalho, Andre Silva, Bernardo Silva, Cristiano Ronaldo, Gelson Martins, Goncalo Guedes, Ricardo Quaresma
Spain
23-man final squad: David de Gea, Pepe Reina, Kepa Arrizabalaga, Jordi Alba, Nacho Monreal, Alvaro Odriozola, Nacho Fernandez, Dani Carvajal, Gerard Pique, Sergio Ramos, Cesar Azpilicueta, Sergio Busquets, Isco, Thiago Alcantara, David Silva, Andres Iniesta, Saul Niguez, Koke, Marco Asensio, Iago Aspas, Diego Costa, Rodrigo Moreno, Lucas Vazquez.
Group C
Australia
26-man preliminary squad: Brad Jones, Mat Ryan, Danny Vukovic; Aziz Behich, Milos Degenek, Matthew Jurman, Fran Karacic, James Meredith, Josh Risdon, Trent Sainsbury; Josh Brillante, Jackson Irvine, Mile Jedinak, Robbie Kruse, Massimo Luongo, Mark Milligan, Aaron Mooy, Tom Rogic, James Troisi; Daniel Arzani, Tim Cahill, Tomi Juric, Mathew Leckie, Andrew Nabbout, Dimitri Petratos, Nikita Rukavytsya
Denmark
35-man preliminary squad: Kasper Schmeichel, Jonas Lossl, Frederik Ronow, Jesper Hansen; Simon Kjaer, Andreas Christensen, Mathias Jorgensen, Jannik Vestergaard, Andreas Bjelland, Henrik Dalsgaard, Peter Ankersen, Jens Stryger, Riza Durmisi, Jonas Knudsen, Nicolai Boilesen; William Kvist, Thomas Delaney, Lukas Lerager , Lasse Schone, Mike Jensen, Christian Eriksen, Daniel Wass, Pierre-Emile Hojbjerg, Mathias Jensen, Michael Krohn-Dehli, Robert Skov; Pione Sisto , Martin Braithwaite, Andreas Cornelius, Viktor Fischer, Yussuf Poulsen, Nicolai Jorgensen, Nicklas Bendtner, Kasper Dolberg, Kenneth Zohore
23-man final squad: Alphonse Areola, Hugo Lloris, Steve Mandanda, Lucas Hernandez, Presnel Kimpembe, Benjamin Mendy, Benjamin Pavard, Adil Rami, Djibril Sidibe, Samuel Umtiti, Raphael Varane, N'Golo Kante, Blaise Matuidi, Steven N'Zonzi, Paul Pogba, Corentin Tolisso, Ousmane Dembele, Nabil Fekir, Olivier Giroud, Antoine Griezmann, Thomas Lemar, Kylian Mbappe, Florian Thauvin
Peru
24-man preliminary squad: Carlos Caceda, Jose Carvallo, Pedro Gallese, Luis Abram, Luis Advincula, Pedro Aquino, Miguel Araujo, Andre Carrillo, Wilder Cartagena, Aldo Corzo, Christian Cueva, Jefferson Farfan, Edison Flores, Paolo Hurtado, Nilson Loyola, Sergio Pena, Andy Polo, Christian Ramos, Alberto Rodriguez, Raul Ruidiaz, Anderson Santamaria, Renato Tapia, Miguel Trauco, Yoshimar Yotun
Group D
23-man final squad: Sergio Romero, Willy Caballero, Franco Armania, Gabriel Mercardo, Cristian Ansaldi, Nicolas Otamendi, Federico Fazio, Marcos Rojo, Nicolas Tagliafico, Marcos Acuna, Javier Mascherano, Eduardo Salvio, Lucas Biglia, Giovani Lo Celso, Ever Banega, Manuel Lanzini, Maximiliano Meza, Angel Di Maria, Cristian Pavon, Lionel Messi, Paulo Dybala, Gonzalo Higuain, Sergio Aguero.
Croatia
24-man revised preliminary squad: Danijel Subasic, Lovre Kalinic, Dominik Livakovic, Vedran Corluka, Domagoj Vida, Ivan Strinic, Dejan Lovren, Sime Vrsaljko, Josip Pivaric, Tin Jedvaj, Matej Mitrovic, Duje Caleta-Car, Luka Modric, Ivan Rakitic, Mateo Kovacic, Milan Badelj, Marcelo Brozovic, Filip Bradaric, Mario Mandzukic, Ivan Perisic, Nikola Kalinic, Andrej Kramaric, Marko Pjaca, Ante Rebic.
23-man final squad: Hannes Thor Halldorsson, Runar Alex Runarsson, Frederik Schram; Kari Arnason, Ari Freyr Skulason, Birkir Mar Saevarsson, Sverrir Ingi Ingason, Hordur Magnusson, Holmar Orn Eyjolfsson, Ragnar Sigurdsson; Johann Berg Gudmundsson, Birkir Bjarnason, Arnor Ingvi Traustason, Emil Hallfredsson, Gylfi Sigurdsson, Olafur Ingi Skulason, Rurik Gislason, Samuel Fridjonsson, Aron Gunnarsson; Alfred Finnbogason, Bjorn Bergmann Sigurdarson, Jon Dadi Bodvarsson, Albert Gudmundsson
Nigeria
30-man preliminary squad: Ikechukwu Ezenwa, Daniel Akpeyi, Francis Uzoho, Dele Ajiboye; William Troost-Ekong, Leon Balogun, Olaoluwa Aina, Kenneth Omeruo, Bryan Idowu, Chidozie Awaziem, Abdullahi Shehu, Elderson Echiejile, Tyronne Ebuehi, Stephen Eze, John Obi Mikel, Ogenyi Onazi, John Ogu, Wilfred Ndidi, Uche Agbo, Oghenekaro Etebo, Joel Obi; Mikel Agu; Odion Ighalo, Ahmed Musa, Victor Moses, Alex Iwobi, Kelechi Iheanacho, Moses Simon, Junior Lokosa, Simeon Nwankwo
Group E
23-man final squad: Alisson, Ederson, Cassio; Danilo, Fagner, Marcelo, Filipe Luis, Thiago Silva, Marquinhos, Miranda, Pedro Geromel; Casemiro, Fernandinho, Paulinho, Fred, Renato Augusto, Philippe Coutinho, Willian, Douglas Costa; Neymar, Taison, Gabriel Jesus, Roberto Firmino
23-man final squad: Keylor Navas, Patrick Pemberton, Leonel Moreira, Cristian Gamboa, Ian Smith, Ronald Matarrita, Bryan Oviedo, Oscar Duarte, Giancarlo Gonzalez, Francisco Calvo, Kendall Waston, Johnny Acosta, David Guzman, Yeltsin Tejeda, Celso Borges, Randall Azofeifa, Rodney Wallace, Bryan Ruiz, Daniel Colindres, Christian Bolanos, Johan Venegas, Joel Campbell, Marco Urena.
Switzerland
TBC
Serbia
TBC
Group F
Germany
27-man preliminary squad: Bernd Leno, Manuel Neuer, Marc-Andre ter Stegen, Kevin Trapp, Jerome Boateng, Matthias Ginter, Jonas Hector, Mats Hummels, Joshua Kimmich, Marvin Plattenhardt, Antonio Rudiger, Niklas Sule, Jonathan Tah, Julian Brandt, Julian Draxler, Mario Gomez, Leon Goretzka, Ilkay Gundogan, Sami Khedira, Toni Kroos, Thomas Muller, Mesut Ozil, Nils Petersen, Marco Reus, Sebastian Rudy, Leroy Sane, Timo Werner.
Mexico
28-man preliminary squad: Guillermo Ochoa, Jesus Corona, Alfredo Talavera; Diego Reyes, Héctor Moreno, Miguel Layún, Carlos Salcedo, Edson Álvarez, Néstor Araujo, Jesús Gallardo, Hugo Ayala, Rafael Márquez; Jonathan dos Santos, Andrés Guardado, Héctor Herrera, Marco Fabián, Javier Aquino, Jonathan González, Jesús Molina y Erick Gutiérrez; Tecatito Corona, Hirving Lozano, Chicharito Hernández, Raúl Jiménez, Carlos Vela, Javier Aquino, Jurgen Damm, Giovani dos Santos
South Korea
28-man preliminary squad: Kim Seunggyu, Kim Jinhyeon, Cho Hyeonwoo, Kim Younggwon, Jang Hyunsoo, Jeong Seunghyeon, Yun Yeongseon, Kwon Kyungwon, Oh Bansuk, Kim Jinsu, Kim Minwoo, Park Jooho, Hong Chul, Go Yohan, Lee Yong, Ki Sungyueng, Jeong Wooyoung, Kwon Changhoon, Ju Sejong, Koo Jacheol, Lee Jaesung, Lee Seungwoo, Moon Sunmin, Lee Chungyong, Kim Shinwook, Son Heungmin, Hwang Heechan, Lee Keunho
23-man final squad: Robin Olsen, Karl-Johan Johnsson, Kristoffer Nordfeldt, Mikael Lustig, Victor Lindelof, Andreas Granqvist, Martin Olsson, Ludwig Augustinsson, Filip Helander, Emil Krafth, Pontus Jansson, Sebastian Larsson, Albin Ekdal, Emil Forsberg, Gustav Svensson, Oscar Hiljemark, Viktor Claesson, Marcus Rohden, Jimmy Durmaz, Marcus Berg, John Guidetti, Ola Toivonen, Isaac Kiese Thelin
Group G
Belgium
28-man preliminary squad: Toby Alderweireld, Michy Batshuayi, Christian Benteke, Dedryck Boyata, Yannick Carrasco, Koen Casteels, Nacer Chadli, Laurent Ciman, Thibaut Courtois, Kevin De Bruyne, Mousa Dembele, Leander Dendoncker, Marouane Fellaini, Eden Hazard, Thorgan Hazard, Adnan Januzaj, Christian Kabasele, Vincent Kompany, Jordan Lukaku, Romelu Lukaku, Dries Mertens, Thomas Meunier, Simon Mignolet, Matz Sels, Youri Tielemans, Thomas Vermaelen, Jan Vertonghen, Axel Witsel.
23-man final squad: Jack Butland, Nick Pope, Jordan Pickford; Fabian Delph, Danny Rose, Eric Dier, Kyle Walker, Kieran Trippier, Trent Alexander-Arnold, Harry Maguire, John Stones, Phil Jones, Gary Cahill; Jordan Henderson, Jesse Lingard, Ruben Loftus-Cheek, Ashley Young, Dele Alli, Raheem Sterling; Harry Kane, Jamie Vardy, Marcus Rashford, Danny Welbeck
Panama
35-man preliminary squad: Jose Calderon, Jaime Penedo, Alex Rodríguez; Azmahar Ariano, Felipe Baloy, Harold Cummings, Eric Davis, Fidel Escobar, Adolfo Machado, Michael Murillo, Luis Ovalle, Francisco Palacios, Richard Peralta, Roman Torres; Ricardo Avila, Edgar Barcenas, Ricardo Buitrago, Miguel Camargo, Adalberto Carrasquilla, Armando Cooper, Anibal Godoy, Gabriel Gomez, Jose Gonzalez, Cristian Martinez, Valentin Pimentel, Alberto Quintero, Jose Luis Rodriguez; Abdiel Arroyo, Rolando Blackburn, Ismael Diaz, Jose Fajardo, Roberto Nurse, Blas Perez, Luis Tejada, Gabriel Torres
Tunisia
29-man preliminary squad: Aymen Mathlouthi, Mouez Hassen, Farouk Ben Mustapha, Moez Ben Cherifia, Syam Ben Youssef, Yohan Benalouane, Yassine Meriah, Bilel Mohsni, Hamdi Nagguez, Ali Maaloul, Khalil Chemmam, Oussema Haddadi, Dylan Bronn, Ellyes Skhiri, Ferjani Sassi, Karim Laribi, Ahmed Khalil, Mohamed Amine Ben Amor, Ghailene Chaalali, Mohamed Larbi, Anice Bardi, Saif-Eddine Khaoui, Saber Khalifa, Naim Sliti, Fakhreddine Ben Youssef, Whabi Khazri, Bassem Srarfi, Ahmed Akaichi
Group H
Colombia
35-man preliminary squad: David Ospina, Camilo Vargas, Ivan Arboleda, Jose Fernando Cuadrado; Cristian Zapata, Davinson Sanchez, Santiago Arias, Oscar Murillo, Frank Fabra, Johan Mojica, Yerry Mina, William Tesillo, Bernardo Espinosa, Stefan Medina, Farid Diaz; Wilmar Barrios, Carlos Sanchez, Jefferson Lerma, Jose Izquierdo, James Rodriguez, Giovanni Moreno, Abel Aguilar, Mateus Uribe, Yimmi Chara, Juan Fernando Quintero, Edwin Cardona, Juan Guillermo Cuadrado, Gustavo Cuellar, Sebastian Perez; Radamel Falcao Garcia, Duvan Zapata, Miguel Borja, Carlos Bacca, Luis Fernando Muriel, Teofilo Gutierrez
Japan
27-man preliminary squad: Eiji Kawashima, Masaaki Higashiguchi, Kosuke Nakamura, Yuto Nagatomo, Tomoaki Makino, Maya Yoshida, Hiroki Sakai, Gotuku Sakai, Gen Shoji, Wataru Endo, Naomichi Ueda, Makoto Hasebe, Yosuke Ideguchi, Toshihiro Aoyama, Keisuke Honda, Takashi Inui, Shinji Kagawa, Hotaru Yamaguchi, Genki Haraguchi, Takashi Usami, Gaku Shibasaki, Ryota Oshima, Kento Misao, Shinji Okazaki, Yuya Osako, Yoshinori Muto, Takuma Asano.
Poland
32-man revised preliminary squad: Bartosz Bialkowski, Lukasz Fabianski, Lukasz Skorupski, Wojciech Szczesny, Jan Bednarek, Bartosz Bereszynski, Thiago Cionek, Kamil Glik, Artur Jedrzejczyk, Marcin Kaminski, Tomasz Kedziora, Michal Pazdan, Lukasz Piszczek, Jakub Blaszczykowski, Karol Linetty, Pawel Dawidowicz, Krzysztof Maczynski, Przemyslaw Frankowski, Slawomir Peszko, Jacek Goralski, Maciej Rybus, Kamil Grosicki, Sebastian Szymanski, Grzegorz Krychowiak, Piotr Zielinski, Rafal Kurzawa, Szymon Zurkowski, Dawid Kownacki, Lukasz Teodorczyk, Robert Lewandowski, Kamil Wilczek, Arkadiusz Milik.
23-man final squad: Abdoulaye Diallo, Khadim Ndiaye, Alfred Gomis, Lamine Gassama, Moussa Wague, Saliou Ciss, Youssouf Sabaly, Kalidou Kalidou, Salif Sane, Cheikhou Kouyate, Kara Mbodji, Idrisa Gana Gueye, Cheikh Ndoye, Alfred Ndiaye, Pape Alioune Ndiaye, Moussa Sow, Moussa Konate, Diafra Sakho, Sadio Mane, Ismaila Sarr, Mame Biram Diouf, Mbaye Niang, Diao Keita Balde