Matt Bloomfield has suffered a cruciate knee ligament injury and will not play again this season.
The Wycombe midfielder picked up the knock in a typically robust challenge during Wanderers' recent home victory over Darlington.
He underwent exploratory surgery on Monday, which then allowed specialists to confirm the severity of the injury.
Bloomfield, who has been with the Adams Park club for four years, is due to have an operation in a month's time and will then face an agonising six months on the sidelines before he can return to first-team action.
"My first question when I came round from the operation was, 'will I be able to play again this season?', but then the doctors told me the bad news," Bloomfield told the club's official website.
"I'm absolutely gutted to be missing so many important games - it'll be torture watching the lads play without being able to help them."
The Blues boss Paul Lambert admits that he is disappointed for Bloomfield, especially as the midfielder's contract is due to expire in the summer.
"This is terrible news for the lad," the Scottish coach told Wycombe's official website.
"Matty has been a huge player for me and he never gives less than 100 per cent.
"He's one of the most popular players with the fans and with the other players and everyone will be devastated to hear the news.
"The timing couldn't have been any worse. He's going to miss the vital run-in to the end of the season and he's obviously concerned about his immediate future, but I'm sure the club will do the right thing."