Aberdeen winger Gary Mackay-Steven is ruled out of tomorrow’s Premiership clash with Hearts.
The 28-year-old has been side-lined since suffering concussion in the 1-0 Betfred Cup loss to Celtic on December 2.
However, he could be fit to face Celtic at Pittodrie on Boxing Day.
Centre-back Mikey Devlin is ruled out until after the winter break with a foot tendon injury sustained on international duty with Scotland last month.
Dons boss Derek McInnes said: “Gary won’t make tomorrow but may face Celtic.
“Michael Devlin will not play until after the winter break.”