Jack Ross fears he could again be without captain George Honeyman when Sunderland travel to Scunthorpe next weekend.
The influential midfielder has been missing since the 3-1 defeat to Portsmouth shortly before Christmas due to an ankle problem.
Ross is hopeful the 24-year-old will be soon be back in action but will see how he progresses this week.
“Probably no more than 50/50,” Ross said.
“If you ask the medical team they would say no, if you asked me and George maybe.
“That sums it up best!
“We have a mini break with no Gillingham game the weekend after next.
“There is an opinion that we would be best served to wait until after that. I value George highly and having him in my squad.
“We will just see how it unfolds this week with regards to him.”
Ross will be boosted by the return of Lee Cattermole, who has now served his suspension for picking up ten yellow cards.
The Black Cats boss is eager to add another striker to his squad after Jerome Sinclair returned to Watford but says he is unsure whether that will happen this week.
“Nothing that I know that is imminent,” Ross said.
“We are working hard on it, obviously.
“I have always been quite straightforward and when I knew somebody was coming in then I would say I expect it to be the case, but I can’t say anything definitely that somebody would be in for then.
“I would hope but nothing imminent at the moment.”
Sunderland are keen on a deal for Will Grigg, who was an unused substitute as Wigan Athletic sealed an impressive 3-0 win over Aston Villa on Saturday.
Wigan boss Paul Cook said on Friday that the 27-year-old does have a future at the club, but is out of the team because of injuries to a number of his creative midfielders.
The Northern Ireland international has four goals from 18 appearances in all competitions this season.