Former Chelsea defender Branislav Ivanovic has told Sport Express that Jose Mourinho is still a special manager despite recent struggles but most footballers would rather spend their careers working under Carlo Ancelotti.

Chelsea allowed Ivanovic to join Zenit St Petersburg last week, bringing to an end a nine-year spell at Stamford Bridge that saw him make 377 appearances and win every major domestic and European trophy, as well as scoring the winning goal against Benfica in the 2013 Europa League final.

During that time the Serbia international earned the trust of both Ancelotti and Mourinho, establishing himself as Chelsea's undisputed first-choice right-back for seven seasons and only losing his place when new head coach Antonio Conte decided to switch the Blues to a 3-4-3 system in September.

Ivanovic's form declined sharply last season as Mourinho was sacked by the club for a second time after presiding over the worst title defence in the Premier League era, but the 32-year-old insists his former manager remains an exceptional coach.

"They call Mourinho the Special One, and I think he is," Ivanovic said. "If you win, his trust knows no bounds. He will make you fulfil the potential you were not even aware of.

"Training was unique under Mourinho. He sometimes plays mind games with the press, but when it comes to the most important things, the matches themselves, he is always very serious. If you want to play for Mourinho, you have to follow his demands.

Branislav Ivanovic won the Premier League title under Jose Mourinho. Darren Walsh/AP Photo

"Mourinho helps to develop the best qualities -- professional and personal. You can't be indifferent to him. You either love him or hate him. That's what makes him special. I am glad that I had a chance to work with him.

"Ancelotti is very different. If players had a choice, I guess they would prefer to spend the entire career with Carlo. He is very calm and takes all the negative aspects on him, allowing the players to be comfortable. The results are equally good with both coaches."

Ivanovic made just seven starts in all competitions over the first half of the season at Chelsea prior to his departure, and says he is looking forward to a new challenge with Zenit.

"I asked [the club] to release me if I received a suitable offer," he added. "Chelsea agreed, and I am very happy with that.

"There was an option to go to China, but I want to play at a decent level and continue my development. That's why I chose Zenit."