London - Liverpool said on Wednesday that forward Sadio Mane had undergone successful surgery on a hand injury he sustained while on international duty with Senegal.

Jurgen Klopp has a number of concerns ahead of his team's return to Premier League action against Huddersfield on Saturday, with doubts over forward Mohamed Salah and midfielder Naby Keita. Defender Virgil van Dijk has been playing despite a rib problem.

"Mane's recovery will be monitored over the next couple of days ahead of the Reds' return to action at Huddersfield Town on Saturday," said a statement on Liverpool's website.

Keita had to be piggy-backed off the field by a Guinean teammate on Tuesday after hurting a hamstring against Rwanda while Salah suffered a thigh problem while on duty with Egypt.

Liverpool are level on 20 points at the top of the Premier League with Manchester City and Chelsea but have gone four games without a win in all competitions.

Mane, 26, started the season brightly but has not scored for Liverpool since September 1.