Fletcher will take charge of the Reds at Burnley on Wednesday evening, following Ruben Amorim’s departure on Monday.
He will be assisted in the dugout by Under-21s staff members Travis Binnion and Alan Wright, plus former team-mate Jonny Evans.
It’s the latest in a number of roles the former Scotland international has fulfilled since returning as a coach five years ago.
When asked why he is always keen to put himself forward and help out, Fletcher’s response touched upon how he'd been moulded as a player and a person by United.
“It’s just the fact that much [help] has been given to me, and I think you can reflect on that when you finish playing as well,” Fletcher told MUTV.