The Spain international has only just recovered from a hamstring issue, but he suffered a setback after appearing as a second-half substitute against Athletic towards the end of last week.
A statement from Barcelona has confirmed that Fati has picked up another problem with his hamstring, although the Catalan outfit have not offered a potential timeframe for his recovery.
"Tests carried out on the first team player Ansu Fati on Friday confirmed that he has a proximal tendon injury in the hamstring of his left leg. In the coming days the treatment to be carried out will be decided," read a statement from the La Liga club.
The 19-year-old has scored five times and registered one assist in 10 appearances for Xavi's side during the 2021-22 campaign.
Fati recovered from a long-term knee problem to make his first league outing of the season at the end of September but has since found it difficult to stay fit. body check tags ::