Celtic boss Brendan Rodgers has conceded there is a big question mark over whether Kieran Tierney will be available to face Rangers at the weekend.
The left-back missed out on Boxing Day as Celtic beat Aberdeen 4-3 at Pittodrie to move three points clear at the top of the Scottish Premiership pile.
Celtic are next in action in the Glasgow derby as they travel to Ibrox to lock horns with Steven Gerrard's Rangers and Rodgers admits that Tierney remains a doubt.
Asked about Tierney, Rodgers told his post-match press conference: "He’s clearly a question mark so we’ll see how he is in the next 48 hours.
"If not, it’s unfortunate but as we’ve seen with the young guys there’s other guys who can come into the squad and it’s an opportunity."
Emilio Izaguirre started at left-back for Celtic against Derek McInnes' men.
As Celtic warmed up for the Glasgow derby by beating Aberdeen, Rangers were dropping two points as they were held to a 1-1 draw at Ibrox by Hibernian.
The Boxing Day results mean that even if Rangers were to beat Celtic, they would be unlikely to be top heading into the winter break due to the respective goal difference of the two sides.