On-loan Wycombe midfielder Scott Donnelly is out for the season after ruptured his anterior cruciate ligament on his knee.
Donnelly, on loan from Swansea, suffered the injury during the 3-2 home win against Chesterfield on December 10.
The Wanderers medical staff had to wait for the swelling to subside before assessing the damage but subsequent scans have revealed the 23-year-old has ruptured his anterior cruciate ligament.
Manager Gary Waddock has backed Donnelly to make a full recovery.
He said: "He feels like one of the lads, he settled in well. The injury he picked up was very unfortunate but he will come back stronger after he overcomes it.
"We will be talking to Swansea regarding what the next step is for him."