With most of the other senior players away on international duty, a United XI lost 2-1 to non-league Stalybridge Celtic with Scotland captain Fletcher by far and away the most experienced member of the squad.
Fletcher, 28, has not played a senior match for United since last November as he has suffered with a chronic bowel condition for much of the past year.
However, he was named in United's Premier League and Champions League squads last week, and his participation in the Stalybridge friendly is an encouraging sign both for the player and United, who have struggled in finding a player to fill his role in midfield in his absence.
Alexander Buttner also featured at Bower Fold, the Dutch defender who joined United recently from Vitesse Arnhem but is yet to make his first-team debut.
Federico Macheda scored first but Celtic fought back well to claim the spoils with a goal 17 minutes from time.