Bristol City defender Louis Carey has suffered a minor setback in his recovery from knee and toe injuries.
Carey, who has not played since the 5-0 defeat at Blackpool on October 1, had hoped to be back in training last week.
However, new manager Derek McInnes says the defender is still 10 days from full fitness while full-back Jamie McAllister is set to return in three weeks.
"Louis has suffered a little bit of a setback and is probably 10 days or so away," McInnes told the club's official website.
"Jamie is pencilled in for around November 21.
"Experience is important for any team and the two of them have been at the club a wee while so it would be nice to see them back on the training ground."