Ghanaian midfielder Prince Buaben suffered a calf injury during Heart of Midlothian's 1-1 draw with Partick Thistle on Sunday.
The 28-year-old picked up the problem towards the end of the half and was replaced by striker Conor Sammon for the start of the second half.
The substitution of the Ghanaian affected Hearts as they conceded an equaliser.
Buaben ha seen a key of Ian Cathro side since the start of the Scottish Premier League.
It's unclear how long he will be out as he will undergo further test on Monday.