Fernandes scored a second-half penalty as United picked up their first home Premier League win of the season against a spirited West Brom side.
"It was an ugly win. Hopefully, that will give them a bit of confidence," United legend Scholes told BT Sport after the match.
"You do feel for West Brom. You do wonder where Man United would be without Fernandes.
"Before Bruno came in, United couldn't create a chance."