Novak Djokovic has revealed today at the press conference in Monte Carlo that he is no longer working with American tennis coach Todd Martin because it became complicated working with two coaches whose styles were different.

"You're always going to have problems like that when you work with two coaches," said Novak. "They did not understand each other very well."

Novak started to work with Martin before last September's U.S. Open and they were mainly work together in American events, but Novak lost in the last 16 at Indian Wells last month and was then beaten in his opening match in Miami a fortnight later.

Novak added that there were specific difficulties when Martin worked on his serve.

"He tried to change [my serve], but it was all too complicated in the end and now I'm back to the old one," said Novak. "Todd is a fantastic person who has so much experience and he shared everything with me but it just did not work out in the end and we separated with no hard feelings.

"I'm full-time with Marian again and hopefully we can have a lot of success."

Novak Djokovic splits from coach Todd Martin