Bryson and Leigh missed the defeat at Celtic Park and the former has been struggling for much of the season.

McInnes said: "Greg Leigh is out for two months. He has a stress fracture on his shin. We got him scanned and had a second opinion and unfortunately he is going to be on crutches for a month.

"On top of that, Craig Bryson saw a specialist on Friday and he is requiring surgery on his ankle.

"It's a real blow. Craig will probably be out, we think, about eight weeks.

"It was an ankle injury he originally got at home to St Johnstone a few months ago. He tweaked it again against Hamilton away and got a tackle against St Johnston again.

"We have been trying to manage a programme but after seeing the specialist, we feel we have no option but to have some minor surgery.

"It's good we have an opportunity to try and deal with that in January but being without two players we signed to be influential players in our team, it's a big blow for us."

Cosgrove's appeal against his dismissal will be heard by a Scottish Football Association panel on Christmas Eve.

The Dons hitman was dismissed after sprinting into a challenge on Celtic defender Kristoffer Ajer.

McInnes expects to have his top goalscorer available for the Boxing Day clash with Livingston at Pittodrie.

He said: "I'm hopeful. The reason we have appealed is because we believe we have a chance to right a wrong.

"I don't think it's a red card but it isn't my decision. I can only look at it and nothing changes my mind on it.

"The speed element only becomes a consideration if he doesn't win the ball.

"If you look, the ball is actually a yard from Ajer, it's not even close. Sam came on the outside to try and win the ball.

"His trailing leg has caught him slightly but that's what happens when you tackle and there's not enough there to hurt the boy.

"Football people see that as a good challenge and for me, it should be overturned."