Chelsea and Arsenal have similar styles - Fabregas
Chelsea midfielder Cesc Frabregas believes his return to London has breathed life back into this career.
The former Arsenal midfielder moved to Stamford Bridge in the summer after three years at Barcelona.
In an interview with Spanish newspaper El Pais, Fabregas said: "Three years ago I wouldn't have imagined working under Mourinho.
"But in the end, life has many turns, and more so in football.
"We had a big rivalry with Mou (Mourinho), we were against him but I never hated him."
During his years at Arsenal and Barcelona, Mourinho was not the only Chelsea figure that Fabregas disliked.
"Chelsea was the team that I wanted to beat the most," he said. "I also had a lot of spats with (John) Terry but in the end, we are people.
"I'm not driven by hate."
Fabregas has moved on from previous on-pitch fallouts to join Chelsea in the summer.
He needed a fresh start after three difficult seasons at Barcelona.
"At Barcelona, things didn't go as I had desired but I'm nevertheless proud of what I did," the 27-year-old said. "I won titles although I was not recognised."
What the Spain international says he has discovered is that Mourinho has many attributes, just as his former Barca coach Pep Guardiola has.
"They are both winners," he said. "They both hate to lose. They are much more similar than people think.They worked differently but they both like to play attractive football."
Fabregas will always have a soft spot for Arsenal coach Arsene Wenger.
"I will always be grateful," he said. "For a young player he is the best coach in the world. You make a mistake and he includes you (in the team), you make another mistake and he includes you, you get booed and he includes you.
"He doesn't care. He believes in you. He always had confidence in me."
Arsenal turned down an option to acquire him last summer, which made it easy for Fabregas to join Chelsea.
"I returned to London because I try to go to the places where I feel loved and happy," he said. "The change from Arsenal to Chelsea from a sporting point of view has not been that big.
"Had I made that change three years ago, I guessed it would have been a bigger adjustment but not now. Chelsea has changed, it's not the team that I expected. Now it's a team that wants to have a starring role.
"It wants to dominate games, have more possession. From a football standpoint is similar to Arsenal."
More importantly, Fabregas feels appreciated.
"I feel really valued and respected more than in Spain but it's normal," he said. "I spent eight years at Arsenal and now I have returned. I'm having a good season. Chelsea has given me security. I am rediscovering myself in football terms.
"I feel important, I wouldn't say as the guiding captain but almost.
"It's just that I play further back and that makes me feel more active in games and hence, I enjoy myself much more.
"I touch the ball 90 to 100 times per game and I missed that.
"I hope I can win everything with Chelsea but I don't want the Champions League to become an obsession."
Once his playing career is over, the World Cup winner with Spain has designs on coaching.
"I'm learning from the best of the best and I feel very fortunate," he said. "I think I have the personality to become a coach but we shall see. I feel I will end up coaching one day."