Sergio Aguero was forced off the field during the first half of Barcelona's clash against Alaves on Saturday, bringing an early finish to just his second start in La Liga since arriving at Camp Nou.
The Argentine was absent for the first two months of the season as he recovered from a nagging calf injury, finally making his club debut in mid-October against Valencia.
And Barca will be hoping that he has not suffered another serious setback as they adjust to life after Ronald Koeman.
What happened?
Almost 40 minutes were on the clock at Camp Nou when Aguero pulled up in discomfort.
The forward was left hurt by a clash in the area and appeared to have trouble breathing, pointing to his chest as he doubled over.
After an assessment from the Barca medical team, he left the game almost in tears, with Philippe Coutinho chosen to replace him in the Catalans' line-up.
Barca were taking on Alaves in the club's first game since Koeman's sacking on Wednesday.
The bigger picture
Injuries have proved a constant concern for Aguero over the past few years.
In 2020-21 the then-Manchester City star was restricted to just 12 Premier League appearances as knee and hamstring problems, as well as a long battle with Covid-19, cast a shadow over what proved to be his last season at the Etihad Stadium.
Fitness issues have also hindered his start at Camp Nou, although he was able to mark his first Clasico with a goal as he netted a late consolation for Barcelona off the bench against Real Madrid last weekend.