Millwall defender Danny Senda is facing nine months on the sidelines while skipper Paul Robinson insists he is happy to stay at the Den.
Senda went under the knife last Wednesday after suffering an horrific knee injury during the final game of the season against Swindon the previous weekend.
"The surgeon was very pleased with the proceedings," said Lions physio Bobby Bacic.
"Danny will now begin the challenge of doing his rehab and we would expect this to take up to nine months due to the severity of the injury."
Meanwhile, Robinson insists he is happy to stay at the Den amid reports linking him with a move to Ipswich.
"It's very flattering to be linked with a Championship club like Ipswich but I am happy at Millwall and as long as that is the case I will continue to give everything I have for this club," he told the South London Press.
"It's a superb place to play football and my job now is to give the supporters the success they crave."