Medical scans have confirmed Hearts defender Michael Smith is out for eight weeks with a torn a thigh muscle.
He suffered the injury near the end of Sunday's Scottish Cup tie against Auchinleck Talbot and underwent a scan on Monday afternoon.
The results confirm Hearts must do without one of their most consistent players until April. "It's probably eight weeks we're looking at," explained manager Craig Levein.
"He has torn his tight muscle, it's a grade two tear but there's a bit of tendon damage as well so it's a bit more complicated. It will keep him out for a fairly lengthy period of time.
"It's a blow for us to lose Michael but we just have to get on with it. There is nothing else for it."
Smith recently extended his Hearts contract until May 2021 but will now be missing as the Edinburgh club enter an important period of the season.
They are challenging for a European spot in the Ladbrokes Premiership and face Partick Thistle in the Scottish Cup quarter-finals next month.