Barcelona defender Thomas Vermaelen may need thigh surgery as his wait for a debut continues.
The 29-year-old centre-back cost the club £15m when they signed him from Arsenal in August.
He has been out since suffering an injury in Belgium's 1-0 World Cup group win over Russia in June although he passed a medical with the La Liga side.
"We are worried for him and the medical staff are evaluating what's best," said sports director Andoni Zubizarreta.
"We don't know if Vermaelen is now going to need surgery. We are studying the situation."