Hearts' worst fears have been realised with the news that Lee Wallace could miss the remainder of the season.
The highly-rated defender broke down while on international duty for Scotland in their Euro 2012 qualifier against Liechtenstein on Tuesday.
He was forced from the field on a stretcher, with early indications suggesting that he had suffered a serious knee injury.
Medical tests on Wednesday have confirmed that Wallace has damaged cruciate ligaments and he is now likely to play little if any further part in the 2010/11 campaign.
"Lee has torn his cruciate ligament, the posterior, and we are looking at six months out of action," Hearts boss Jim Jefferies told the club's official website.
"It appears his season is all but over and that is a hammer blow, first and foremost for the lad as everything seemed to be falling into place for him.
"His form had taken him into the international team, he had taken over the captain's armband with Marius (Zaliukas) out and had been doing really well.
"It's also a major blow for the club and the team and it goes without saying everyone at the football club wishes him well with his recovery."
Wallace is set to visit a specialist in London over the next few days in an effort to determine whether he will require surgery.
The injury blow has rocked Jefferies' plans for the remainder of the campaign, as he must now shuffle his defensive options.
He added: "These are the things that football can throw at you and we'll just have to deal with it.
"We have had to play guys out of position before and we'll just have to try to fill the void as best we can."