Dylan McGeouch is out for eight weeks with a groin problem, Aberdeen boss Derek McInnes has revealed.
The Dons midfielder sustained the injury in Sunday's 3-3 Premiership draw with Celtic at Pittodrie and will miss this Sunday's William Hill Scottish Cup semi-final against the Hoops at Hampden Park as well as the next two months.
As he assessed his squad's fitness ahead of the trip to Glasgow, McInnes described McGeouch's prognosis as the "worst" possible amid some otherwise positive news.
He said: "Dylan is out for eight weeks with a groin problem.
"He tore it just as he came off the side of the pitch, there is a little lip there, about a yard before you go on to the trackside.
"He lost his footing on that and overstretched that. Unfortunately, it was the worst news possible on that one.
"Ryan Edmondson got a slight concussion from when he got smashed into the boards but thankfully he will return to training on Friday.
"He has gone through all the protocols and is absolutely fine and will train on Friday.
"Marley (Watkins) came off with a hamstring issue and – while he hasn't trained with us – his scan is clear and he will train on Thursday and Friday ahead of Sunday's game.
"The other boys we wanted to get some game time into this week all came through yesterday's bounce) match with no issues.
"Mikey Devlin, Matty Kennedy, Greg Leigh and Curtis Main, they all got valuable game time, Sam Cosgrove as well, so those ones have given us a real boost that they are getting closer to where we need them to be and start to give us more options."
