Derek McInnes is sweating over the fitness of on-loan Derby left-back Max Lowe as Aberdeen prepare to host Ladbrokes Premiership leaders Celtic at Pittodrie on Boxing Day.
Lowe, 21, has been a standout performer for the Dons in the first half of the season, and his impressive form has led his parent club to recall him in January.
However, after being forced off through injury just after half-time in the Sam Cosgrove-inspired 2-0 win over Hearts, Lowe may already have made his last Aberdeen appearance.
McInnes said "We'll get Max in on Sunday to check him out and see how he is. He puts a lot of yards in and runs with high intensity so hopefully it's not too bad, but you'd have to say he's a doubt with the game coming so quickly.
"There's two games left in a busy month of football, and it looks as though we've got four defenders out for those ties."
McInnes hopes the Dons can extend the Christmas cheer for their fans by providing a win over Celtic that would take his side level on points with the champions.
"If we can be as strong as we can in terms of selection and physically, what a game it will be," he said. "You always want the Boxing Day game to be at home anyway, but you saw the crowd today – they had fantastic support for the players, and we'll need that and more against Celtic.
"They are the best team in Scotland, but they're a team we feel we can beat, and the fact we go into the game with a lot players in a good place, we're confident and we'll have a full house. Hopefully these ingredients help us."
Early leaders Hearts have seen their form slump over the past couple of months, with just one win in their last 10 games in all competitions, and Craig Levein hopes to stop the rot during the visit of Hamilton on Wednesday.
"I expect a tough match," he said. "This season, more than any other I can remember, anybody seems to be able to beat anybody else on a given day. We'll need to be good. I was obviously much happier today than I was last Friday, and I saw definite signs of progress.
"We've still got limitations in the forward areas and that will improve when we get Uche Ikpeazu back and also David Vanacek in. Steven Naismith coming back in definitely helped without a shadow of a doubt, and I just wish the game was sooner to get this bad taste out of my mouth."
