The Brazilian pair have tested positive for COVID-19, meaning they now have to isolate, in line with Government guidelines.
Telles missed Friday’s home game with Middlesbrough in the Emirates FA Cup, with it emerging he returned a positive test prior to the game.
His compatriot Fred, who came on as a substitute against the Teessiders, has now also tested positive and he could also be a doubt for Saturday’s game with Southampton at Old Trafford as a result.
“Yeah we have two players missing,” Ralf told club media as part of his exclusive pre-match interview.
“Alex Telles already missed the cup game because he tested COVID positive last week and, unfortunately, the same thing happened today with Fred.