Bolton Wanderers manager Owen Coyle is concerned Marcos Alonso has suffered another foot injury after the defender was forced off in the win at Blackburn Rovers.
Alonso has only recently returned to action after he sustained a fractured metatarsal against Macclesfield Town in the Carling Cup in August.
The 20-year-old started his first Premier League game of the season in last weekend's defeat at Fulham and retained his place for Tuesday's derby at Blackburn.
However, the former Real Madrid youngster was replaced by Paul Robinson in the second half after he left the field with his boot removed.
He is now due to undergo an X-ray to assess the damage and Coyle is worried Alonso may have suffered a repeat break.
"The disappointing thing was that Marcos picked up an injury," said Coyle.
"We have sent him for an X-ray because we are concerned he has fractured the same foot again. Hopefully not, but we will see."