The Red Devils head to the Stadium of Light on the back of their 1-1 draw with Chelsea at Stamford Bridge last weekend and looking to secure victory to keep their top-four hopes on track.
United are currently fifth in the Premier League table and six points behind Manchester City in fourth as they head into the final 13 games of the season.
Former Arsenal man Merson feels that the Red Devils have turned a corner in recent weeks following their stuttering form in the Premier League and is backing them to head back to Manchester with three points on Saturday.
Merson told Sky Sports: “Manchester United have turned the corner, I’ve been impressed. They looked really good at Chelsea and thoroughly deserved a draw at least.
“Sunderland, meanwhile, will have felt they did well against Man City, despite losing, and then they got a lucky draw at Liverpool if I’m being honest.
“We will have to see whether the speculation surrounding Louis van Gaal’s future affects United but they seem to have turned the corner and I expect them to win at the Stadium of Light.”
United have only won three of their last 10 Premier League games and were dumped out of the Champions League at the group stage back in December.
MORE: Latest Man Utd news
MORE: Latest Arsenal news
MORE: The latest football news