Atletico Madrid are facing an anxious wait to learn the full extent of a thigh injury suffered by David Villa in the win over Real Sociedad.
The Spain striker's withdrawal after 41 minutes was the only downside to a superb performance against Sociedad on Sunday, as Diego Simeone's men claimed outright leadership of La Liga with a resounding 4-0 win.
Villa had opened the scoring with a close-range finish to set Atletico on their way, but he was then forced off just three minutes later to be replaced by Raul Garcia.
The club subsequently confirmed that an initial scan had shown a "muscle injury on the back of the left thigh".
Villa will undergo further medical tests next week to ascertain the seriousness of the problem.
The news took the shine of an otherwise superb day for Atletico, who sealed victory and top spot in the table as goals from Diego Costa, Miranda and one from new signing Diego added to Villa's early strike.