Middlesbrough defender Calum Chambers could be out for several weeks after suffering a stress fracture in his foot.
The 22-year-old, who is on a season-long loan deal at the Riverside Stadium from Arsenal, is yet to discover the full extent of the problem, with head coach Aitor Karanka keeping his fingers crossed that he can return sooner rather than later.
"It's a stress fracture in his foot. I don't know how long [he will be out] because sometimes you think it's going to be one or two weeks and maybe it's three or four," Karanka said. "I don't know. At the moment, he's trying to be [fit] as soon as possible.''
Chambers will definitely miss Saturday's FA Cup fourth round clash with League Two Accrington, and with West Brom's Premier League trip to Teesside coming just three days later, he seems certain to sit that one out too at the very least.