Bolton Wanderers will be without captain Antoni Sarcevic for up to a month after the midfielder picked up a groin injury in the loss against Tranmere Rovers.
The 28-year-old has scored five goals in 25 games for the Trotters in all competitions this season.
But Wanderers will be without the skipper on Saturday for the visit of Leyton Orient and may not have him back until the end of March..
Bolton manager Ian Evatt said: "Antoni Sarcevic will be out for a month. He hurt his groin in the last game at Tranmere, so we’ve had it scanned and he’s got a muscle injury which will keep him out for three to four weeks.
"It's a blow because he's one of our marquee players, marquee signings and he's the captain of the team.
"He's had a scan and has a Grade 2 of one of the many ligaments around the groin area so we'll miss him for three to four weeks.
"It's a blow there's no doubt but it's part of football and we have to adapt and overcome.
"It gives an opportunity for others to come in and stake a claim. We're also trying to strengthen the squad so we'll see how we cope without him on Saturday."
But there was more positive news on the fitness of two of the January transfer window acquisitions.
Declan John is yet to play for the Trotters since joining on loan from Swansea City, while Kieran Lee missed the last game against Rovers after coming off at half-time against Cheltenham Town.
Evatt confirmed that former Sheffield Wednesday midfielder Lee is ready to make a return, while John will be part of the matchday squad against the O's and potentially come off the bench for his debut.
The Bolton boss said: " Declan John and Kieran Lee are back training, fully fit and ready to go.
"Declan probably won’t make the starting XI on Saturday, but he’ll be involved. Kieran Lee is fit and ready to go and Shaun Miller is almost back with us as well."
