Marcelo Bielsa says Leeds United loanee Eddie Nketiah will resume full training next week as he continues to step up his return to action.
The Arsenal forward has been sidelined in recent weeks with a lower abdomen issue which he picked up ahead of the league victory over Queens Park Rangers at Elland Road earlier this month.
Nketiah was due to make his first Championship start against the Rs under Bielsa since joining the Whites ranks in the summer before injury left him in the Thorp Arch treatment room.
The Argentine also revealed United are facing a wait over club captain Liam Cooper (hamstring) and midfielder Jamie Shackleton (quad) while Adam Forshaw (hip) remains out.
Gjanni Alioski (hip) has been passed fit as has utility man Stuart Dallas after he was left nursing a hamstring problem following international duty with Northern Ireland.
Speaking ahead of the trip to Luton Town, Bielsa said: "We don't know if Cooper is going to play yet. Dallas and Cooper are healthy but we will have to see.
"Nketiah is not ready yet, but next week he will start working with the group. Gjanni Alioski is (also) good."
Asked about a potential return date for Nketiah, he added: "He is training.
"It’s different when you train to when you train with the group and after it is necessary to consider the time he was without training. For instance, Dallas played on Saturday, five days ago and Cooper 12 days ago.
"So there are different situations between Dallas and Cooper. After Eddie starts to train with the group, he will be ready to compete.
"One thing is being healthy and another being ready to compete. It is necessary to consider the time he was without training."