Lewis Grabban will miss the next two Nottingham Forest games as the club waits to learn just how long he will be out for.
The striker sat out the games against Luton Town and Middlesbrough after injuring his hip against Derby County.
Manager Chris Hughton says he is unsure exactly how long Grabban will be out at this stage ahead of home games against Coventry City and Wycombe Wanderers before the international break.
"We're looking very much at an assessment in the international break," the manager told Nottinghamshire Live.
"It's to be determined how long he is out for. The assessment afterwards was that it will be weeks as opposed to days.
"I suppose it's about he reacts to the injury that determines how long he is out for.
"Is it a worry? We have to cope with it and you all always want your best players.
"Grabban, as we know, is one of our players over the last couple of seasons who has produced well for the club."
In more positive news, midfielder Harry Arter has overcome an ankle injury and is available to face Coventry after missing two matches.
The Reds will once again also be without injured trio Joe Worrall, Tyler Blackett and Fouad Bachirou.
Worrall is ruled out with a broken foot, midfielder Bachirou has a hamstring injury and Blackett is sidelined with an unspecified problem.
