Concussion has ruled Hearts defender John Souttar out of Sunday's Tynecastle Park reopening against Partick Thistle.
He could also miss the following weekend's visit of Ross County with the injury, sustained on international duty with Scotland Under-21s last Friday.
Souttar was kept in hospital overnight on Friday after suffering a heavy knock to the head, which forced him off after 68 minutes of Scotland's 1-1 draw with Latvia in a European Under-21 Championship qualifier at McDiarmid Park.
He returned to Riccarton over the weekend but Hearts medical staff immediately ruled him out of the Partick Thistle match. Hearts are due to open their new main stand against Partick but Souttar will miss out, and his availability for Ross County also looks doubtful.
"He got quite a bad bang on his head and was concussed, so they kept him overnight in hospital," explained the Hearts manager, Craig Levein.
"He's going to struggle for this week and possibly the following week as well. It's unfortunate, obviously. It was quite a bad knock he got so with these things we have to be ultra careful."
Souttar, 21, captained Scotland in Friday's match but left the squad following his release from hospital. He will not take part in the Under-21s' next qualifier against Ukraine on Tuesday night.
"John asked to come off," said the Scotland Under-21 coach, Scot Gemmill. "We have a duty to obviously protect him in that way so as soon as he indicated that he needed to come off."