FIFA has confirmed that Olympic soccer rosters can include 22 players, but only 18 can be available for individual matches.

Traditionally, Olympic rosters are 18 players and four alternates. The alternates can only be used in case of injury, and once replaced, a player cannot return.

The change means that all 22 players are available to the participating teams. It was implemented because of the challenges the coronavirus has posed to teams worldwide.

"The International Olympic Committee (IOC) has made official a more flexible approach towards the participation of the alternate athletes in the Olympic Football Tournaments Tokyo 2020.

"As a result, the Participating Member Associations will be entitled to reconstitute their teams ahead of every match," FIFA said in a statement to The Associated Press.

"The number of athletes on the start list will therefore remain at 18, but teams will now have the total of 22 players (18 Athletes + 4 Alternate Athletes) to select their team from for every match.

"The IOC has also remarked that this is an exception for the Tokyo 2020 Games and does not create a precedent for future Olympic Games," the statement said.

Netherlands coach Sarina Wiegman was among those who advocated for roster expansion. FIFA, soccer’s international governing body, appealed to the IOC.

The expanded rosters should give coaches more flexibility during a tight Olympic schedule with limited rest time between matches, as well as expected heat and humidity in Tokyo.

Olympic rosters differ from those allowed for the World Cup, which includes 23 players. Historically at the Olympics, an alternate could be brought in for an injured player at any time during the tournament, whereas World Cup rosters are set as of the first match and injured players can’t be replaced.

US women's national team coach Vlatko Andonovski on Wednesday said the teams were awaiting additional guidance from the IOC.

"We're getting word from the IOC that we will have a little flexibility on the roster. We’re very happy about it, and as of right now we’re just waiting to see a little more details on what all the rules and regulations are going to look like," Andonovski said.