Celtic full-back Emilio Izaguirre has resumed full training as he steps up his recovery from a broken ankle sustained in early August.
The Honduran was hospitalised after leaving the field just 15 minutes into a 1-0 win at Pittodrie and a six-month recovery was predicted.
Defensive team-mates Cha Du-Ri, Thomas Rogne and Kelvin Wilson are also fit enough to join in full training.
Wilson last played in a League Cup victory at Ross County on 21 September.
Manager Neil Lennon revealed that Izaguirre was anxious to return to the first team but warned that no risks would be taken with last season's player of the year in Scotland.
"He's just desperate to play," said Lennon.
"He's targeted a game coming up but the medical team are going to be very careful with him.
"I don't envisage him being back for the next couple of games. It's difficult for me to put a time scale on it
"He's been out for a long time and it was a complicated injury."
Joe Ledley was carried off during Wednesday's 1-0 defeat to Atletico Madrid but the midfielder could be fit for Sunday's trip to Dundee United.
"It is a twist on the ankle for Joe," said Lennon. "We will have to see how he is but I don't think it is anything too serious."