Hearts winger Andy Driver may undergo further surgery this week and could miss the rest of the season.
The 23-year-old had a summer operation in Sweden and only returned to action in January.
But he has since been troubled by niggling thigh strains and has only made three SPL starts this term, with his latest outing as a 75th-minute substitute in the 2-2 draw against Kilmarnock on Saturday.
Hearts boss Jim Jefferies said the injury problems have affected the highly-rated winger.
He told the Daily Record: "The big blow is that Andy has battled on for as long as possible now and it has affected him.
"There is a possibility he might be going for an operation prior to Saturday. We'll have to wait and see."
On a more positive note, Jefferies may have injured defender Andy Webster back to face Rangers on Saturday, although the game looks to have come too early for Lee Wallace.
The Hearts boss added: "Andy has seen a slight improvement so we're keeping our fingers crossed he'll be okay for the Rangers game.
"We reckon Lee could train with us today but Saturday just might be too early for him."