Millwall are set to add Josh Wright to their squad.
The former Scunthorpe midfielder this week signed a short-term contract with the Lions after impressing on trial.
Boss Kenny Jackett moved for Wright as utility man Tamika Mkandawire is facing a spell in the treatment room after a knee operation.
Jackett will check on goalkeeper David Forde, who was forced to withdraw from the Republic of Ireland squad last week due to a thigh injury.
Steve Mildenhall is on standby to make his fifth appearance of the season if Forde is ruled out.
Jackett is still without strikers Josh McQuoid, who has a thigh problem, and John Marquis following a recent hernia operation.
Bristol City will be without fringe players Ryan Taylor and Nicky Hunt.
Striker Taylor (broken metatarsal) and full-back Hunt (knee) face up to two months on the sidelines after sustaining injuries in the Robins' Gloucestershire Senior Challenge Cup victory over Mangotsfield United on Tuesday night.
Manager Derek McInnes will also assess defensive pair Louis Carey (knee) and Jamie McAllister (ankle).
The pair missed the 3-1 victory over Burnley which was McInnes' first home win as Robins boss.
But the international break may have provided sufficient time for the duo to return to full fitness.
Striker Brett Pitman will be hoping McInnes opts to put him in his starting line-up after he netted against Burnley despite starting on the substitutes' bench.
