But the Spain goalkeeper will be disappointed to have conceded a soft goal on what was essentially the only time he was called into action in the full 90 minutes.
With half-time approaching and, after comfortably fielding two low balls in his first 42 minutes of action, he was beaten at the near post by a Jerome Sinclair drive as the visitors cancelled out Nick Powell's header.
United won it thanks to Paddy McNair's powerful strike shortly after half-time, but Valdes was barely called into action for the rest of the game on what was his first appearance of any description since injuring his knee last March.
It was the Red Devils' first victory in five U21s Premier League matches, following two defeats and two draws in their last four outings.
Valdes signed an 18-month deal with United earlier in January after training with Louis van Gaal's side for several weeks.
The Spain goalkeeper was set to move to Monaco after running down his contract at Barcelona, but the switch was called off by the Ligue 1 club after he was injured during last year's match against Celta Vigo.
He had been linked with a move to Liverpool in the final days of the summer transfer window, and continuing into September and October, but eventually joined United.
Out-of-favour midfielder Anderson, expected to leave the club on a free at the end of the season, played 88 minutes on Monday, while Darren Fletcher, who has courted interest from West Ham in recent days, was not named in the squad.
