Barcelona boss Pep Guardiola admits injury concerns over Xavi after victory against Valencia.
Xavi was returning from an Achilles problem and was instrumental in Barca's comeback, setting up the goals for Andres Iniesta and Carles Puyol to cancel out Pablo Hernandez's 37th-minute strike.
But the 30-year-old was clearly in pain late on and was replaced by Javier Mascherano after 77 minutes - and Guardiola fears his playmaker may be restricted to a less regular role in future.
"My feeling is that he won't be able to play week in, week out, but we will see how he is and how the problem evolves over time," he said after the match.
Xavi is now doubtful for Barca's Champions League match at home to FC Copenhagen on Wednesday.
"We will see how he is when he gets up tomorrow, but we won't take any chances," Guardiola said.
