John Obi Mikel is adamant Jose Mourinho has not lost his magic as Chelsea prepare to take on Manchester United and has backed his former manager to guide the Old Trafford side back to greatness.
Mourinho has endured somewhat of a difficult start to life at United, losing to Pep Guardiola's Manchester City and also suffering defeat at Watford, but Mikel has little doubt he will turn things around over time.
United will arrive at Stamford Bridge on Sunday with all eyes on Mourinho as he returns to Chelsea for the first time since being sacked last year and Mikel warned his team-mates not to underestimate their former boss.
"I have no doubts, Mourinho has not lost any of his magic, not at all," Mikel told the Evening Standard.
"When people start to question his qualities, he loves to prove a point, he thrives on it. He always wants to show people are wrong.
"I think he will bring Manchester United back to where Sir Alex Ferguson left them [as title winners in 2013] but he needs time.
"He is like an architect, he likes to build. Jose does not always win the title in the first season, just look at Real Madrid or his second spell at Chelsea.
"Yes, he wants to win from the get-go but in the first year he gets to know how the club work, installs his formation and the way he wants the team to play.
"I am not writing United off this season either but give him two to three years and he will definitely win big trophies at Old Trafford."