Desailly believes that Mourinho is still having to shoehorn players into his squad that he does not want, however, and has backed the three-time Premier League title winner to eventually get it right at Old Trafford.
"He has to stay as Mourinho. He knows the capacity of his team," the Frenchman told Omnisport. "He looks like he's not really had the team he wanted, like when you compare with [Pep] Guardiola, who really chose every player he wanted in and out.
"Mourinho, he's still dealing with some players that he didn't really want in his system. He's doing well, so I hope United will shine like they were shining at the time with [Alex] Ferguson.
"But it's tough. Every time, every game, there's big history on the shoulders of all the players and on the manager. So, let's give him time."
Desailly spent six years at Chelsea during his playing days, winning the UEFA Super Cup in 1998 and FA Cup two years later.