Interim manager Ole Gunnar Solskjaer has made a remarkable impact, winning nine and drawing one of his 10 matches in charge across all competitions.
While a move away from Mourinho's pragmatism has seen the likes of Paul Pogba, Marcus Rashford, Anthony Martial and Lingard flourish.
Phelan, who also served as an assistant to Alex Ferguson, returned alongside Solskjaer, and together Lingard thinks they have brought back that 'old school feeling'.
"Solskjaer and Mike Phelan have brought back the old school Manchester United," Lingard told the Daily Mail.
"They know the league and the club inside out, so to pass that on and get us playing how we are has been perfect.
"Solskjaer is doing very well. Nobody can fault him. He has taken a lot on, but he already knew what he was doing when he came in. He got the players backing him straight away.
"He told us there are big expectations and pressure at this club, but we have to deal with it and play like a real United team.
"We will challenge for the title next season if we carry on how we are now. We're back to basics and winning games by grinding out results or scoring a lot of goals. As long as we're winning games, that's all that matters."