Barcelona defender Thomas Vermaelen has reportedly suffered a setback in his recovery from injury.
The Belgian, who joined from Arsenal in a £15m deal last summer, is still waiting to make his debut club due to a string of injury problems.
Reports last week suggested that he was closing in on a return to action after surgery on his thigh.
However, the Daily Mail claims that Vermaelen complained of muscle pain during light training, and it is unclear whether the 29-year-old will play this season.
Vermaelen signed a five-year deal when he arrived at Camp Nou in August.