Barcelona have confirmed that key midfielder Pedri suffered a hamstring problem during Thursday's Europa League contest with Manchester United at Camp Nou.
The 20-year-old has been a vital player for Xavi's side during the 2022-23 campaign, scoring seven goals in 30 appearances in all competitions.
Pedri was again in the starting side for Thursday's Europa League knockout round playoff first leg with Man United, which ended in a 2-2 draw.
However, the Spain international was forced off in the latter stages of the first half through injury, and Barcelona have now confirmed that the youngster picked up an issue with his hamstring.
"FC Barcelona's Pedri has injured the rectus femoris muscle in his right thigh (hamstring). Following tests on Friday morning the damage has been confirmed and he will be unavailable for selection until his leg has recovered," read a statement on the club's official website.
"The Canary Islander went down hurt towards the end of the first half of the Europa League game with Manchester United at Spotify Camp Nou this Thursday.
"The news comes as a real blow to Barca, for Pedri has been in tremendous form of late and has played a key role in the long unbeaten run."
Speaking after the clash with Man United on Thursday, Xavi said that the midfielder had "quadriceps discomfort", which led to his withdrawal.
"It's a very significant loss but we'll try not to let it show. We have alternatives such as Frenkie [de Jong], Sergi [Roberto] and Pablo [Torre]."
A timeframe for Pedri's recovery has not been set, but according to ESPN, he could be missing for the next month due to the nature of the issue.
Fellow midfielder Gavi is also out of the return leg at Old Trafford due to suspension, while Sergio Busquets remains a doubt due to an ankle sprain, although the latter is expected to return to training on Friday.
"Well, on paper, this is going to be a very intense game at Old Trafford," Xavi added ahead of the second leg with Erik ten Hag's side. "Even more intense. We go to Old Trafford to compete again and will see what happens.
"It was a tight game against a tough rival, one of the best in Europe. So I'm currently proud of my team, in spite of the draw.
"We were looking to surprise them [with the line-up], not to respond to Manchester United's approach. They have a powerful armoury and a great team with high-level players and an amazing coach."
Barcelona will now be looking to return to winning ways on Sunday evening, with Cadiz the visitors to Camp Nou in La Liga.