Antonio Valencia's late return from international duty could force Manchester United manager Jose Mourinho to alter his side in next week's derby against Manchester City.
The 31-year-old doesn't return to Manchester until Friday, the day before the derby, as he is travelling with Ecuador to face Peru in a World Cup Qualifier.
Valencia, who is on the shortlist for the Premier League's Player of the month for August, has had an impressive start to the season.
"The day before Man City, we will still have Sergio Romero, Marcos Rojo and Antonio Valencia arriving," Mourinho said to the club's official website.
"It will be a complicated process but we know it is like this when we have these players. And I would love all of the players to go because it would mean that everybody is being selected for their national teams."
Phil Jones, Matteo Darmian or Timothy Fosu-Mensah could make their first appearance of the season if Valencia is not ready to start in the right-back role against Manchester City, live on Sky Sports.
Fellow defender Luke Shaw has underlined the importance the fixture could have in the title race, as both Manchester clubs come into the fixture with a 100 percent winning record from the opening three games of the Premier League season.