Barcelona striker, Sergio Aguero, has been taken to hospital for a heart examination, after experiencing chest pain during their 1-1 draw with Alaves on Saturday night.
The 33-year-old was substituted before half time, after being attended to on the pitch by Barca's medical team.
Aguero was eventually able to walk off the field by himself, before being transferred to hospital, where tests will be carried out to determine the nature of the problem.
"The first team player, Sergio Aguero reported chest discomfort and has been admitted to the hospital for a cardiac exam," Barca said in a terse statement after the game.
Barca also lost Gerard Pique to a calf strain against Alaves to further increase their injury woes.
Sergi Roberto, Ronald Araujo, Pedri, Frenkie de Jong, Ansu Fati, Ousmane Dembele and Martin Braithwaite all missed Saturday's game with various fitness issues.
Aguero, who joined Barca from Manchester City in the summer on a free transfer, only made his debut for the club earlier in October after he injured his calf in preseason training.