Hearts manager Craig Levein was rocked by the news that Craig Halkett is facing months on the sidelines after suffering a medial ligament injury in his knee in the goalless draw at St Mirren.
The 24-year-old defender was handed the captain's armband in Christophe Berra's absence but had to be replaced in the 22nd minute after an innocuous challenge with Kyle Magennis.
The Jambos currently have nine first-team players unavailable and Levein cut a deflated figure after hearing the severity of Halkett's injury.
"My biggest disappointment of the day was Craig Halkett's knee injury," the Scot said.
"Last week was the first time that we've played a match where we've not had to take somebody off before half-time. I thought we'd got over that but I've had to take two players off today before half-time.
"It's just a freak challenge, the boy has caught him on the outside of his knee and forced the inside medial open. It's damaged the ligament and he could be out for quite a while.
"He had the captain's armband on today because of his performances. I feel so sorry for him because he was really stepping up, finding his groove and becoming the really important player that I thought he would be.
"I'm sick for him and that's another of our best players on the sidelines. I can't pinpoint any reason why we should pick up so many injuries and 90 percent of them are in games which I find extraordinary."
The injury overshadowed an unspectacular game as Hearts looked to be suffering from fatigue after Wednesday's penalty shoot-out cup win over Aberdeen.
Chances were at a premium with Steven MacLean stabbing an early chance wide before a moment of controversy as the hosts had an effort ruled out for offside.
Tony Andreu smashed the ball low past Joel Pereira but after initially hesitating, Douglas Ross correctly flagged for offside after deliberation with Andrew Dallas.
Both sides had chances to win it in the final 15 minutes, MacLean failing to get on the end of Uche Ikpeazu's delightful pass before Buddies substitute Jon Obika fired wide late on.
St Mirren boast the best defensive record in the league outwith the Old Firm and Jim Goodwin was upbeat with a point.
"We have to be realistic because Hearts are a top four or five club and despite wanting to win the game, it's a valuable point," he said.
"It's our third clean sheet of four home games at home. We need to try and be more adventurous and courageous to go and take the game to the opposition."
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