The Brazil international suffered a knock in training and could miss the start of the 2021-22 campaign.
Alex Telles has picked up an ankle injury that will see him remain on the sidelines for “a few weeks”, Ole Gunnar Solskjaer has confirmed.
Telles was not included in Manchester United’s matchday squad for the friendly against Queens Park Rangers on Saturday.
Having twisted his ankle at the club’s training camp at Pennyhill Park, the left-back will also likely play no part in the next three pre-season warm-up games.
The Red Devils face Brentford up next and then take on Preston before concluding their pre-season with a match against Everton.
August 14 will see them kick off their new Premier League campaign by locking horns with bitter rivals Leeds United at Old Trafford.
“Unfortunately, Alex slipped and he twisted his ankle so he’ll be out for a few weeks,” Solskjaer told MUTV.
“We hope it’s not too bad.”
Telles, who moved to United from Porto last summer, was afforded limited game time in 2020-21 after falling down in the squad pecking order to a rejuvenated Luke Shaw.
The 28-year-old has been linked with a move away from Old Trafford this summer, with interest reported from Serie A.