Midfielder Paul Pogba is a doubt for Manchester United’s first Premier League game of the new season against Crystal Palace on 19 September.
Pogba missed France’s Nations League double-header last week after testing positive for coronavirus.
Manager Ole Gunnar Solskjaer said Pogba has returned to training but is not certain to feature against Palace.
“Paul’s lost out on a few sessions because of the virus,” Solskjaer told MUTV.
“He is quick to get fit and hopefully he’ll be ready for next weekend. I am not 100% sure though.”
Pogba missed much of last season with injury before returning after the Premier League’s restart to play a key role in Solskjaer’s side.
United do not play on the opening weekend of the 2020-21 campaign because of their participation in the 2019-20 Europa League in August.