Former world doubles No. 1 Max Mirnyi has joined Kei Nishikori's coaching staff, the Japanese star told Kyodo News on Saturday.

The 29-year-old Nishikori, ranked 13th in the world, had been coached by Dante Bottini from 2011 until this year. Mirnyi is a 42-year-old from Belarus who got as high No. 18 in the world in singles.

(Max Mirnyi)[Getty/Kyodo]

"His (Mirnyi's) playing style is a little like mine," Nishikori said. "He's extremely serious and direct."

Former French Open champ Michael Chang will stay on to provide support for Nishikori in big tournaments.

Nishikori has not played since his third-round exit at this year's U.S. Open and had right elbow surgery in October. He has been undergoing rehab work in Tokyo and is now able to swing his racket slowly to strike sponge balls.

He indicated his first target is taking part in the ATP Cup team tournament, starting Jan. 3.

"If I don't panic, I feel I'll be fit in time for the Australian Open (starting Jan. 20)," Nishikori said.