Hearts fear striker Kevin Kyle could require surgery to cure his long-standing groin problem.
Kyle, who has scored 10 times this season, has missed the last five matches after being substituted during the Scottish Cup loss to St Johnstone on 11th January.
His groin problem has been treated with injections and Hearts boss Jim Jefferies hopes it is improving, but the Scotland striker could yet go under the knife.
"We're keeping our fingers crossed that if he doesn't make Saturday, he'll be back fairly soon," Jefferies told the club's official website.
"We're trying to hold off an operation, so there have been a series of injections which have taken a little bit of time to get to the part that's causing the problem.
"The worst scenario is if there's no improvement we may have to be forced to go down the line of an operation. We're keeping our fingers crossed that doesn't happen."