Aberdeen will be without injured midfielder Ryan Jack for Saturday's League Cup semi-final against St Johnstone.
The 21-year-old was carried off on a stretcher following a challenge from Motherwell defender Shaun Hutchison in a
2-2 draw at Fir Park.
Jack is expected to be sidelined for up to eight weeks with a hip injury.
"Ryan suffered a double tear in the hip area and will now sadly miss our semi-final this weekend," the club said.
Derek McInnes thought Hutchison deserved a red card.
"I thought it was a poor challenge," he said at the weekend.
"I know there is a touch on the ball from Hutchison but for me there is only someone going to get hurt in that challenge.
"It is reckless at the very least. "In real time I did wince. I thought it was a straight red and having seen it again, I think you would lean more towards a red than a yellow."
Motherwell manager Stuart McCall said the tackle was "robust".
But he defended his centre-back, adding: "Shaun 100% wins the ball, there is no doubt. It's a yellow card in my eyes."
Aberdeen face Tommy Wright's side at Tynecastle for a place in the League Cup final.