By Chris Oddo | @TheFanChild | Thursday July 24, 2019

Alexander Zverev and coach Ivan Lendl have finally called it quits after a tumultuous partnership.

The German hired Lendl ahead of last year’s U.S. Open and the partnership has yielded a 9-4 record at the majors and a string of disappointing performances on the tour this season, where Zverev has produced a 25-14 record with one title while simultaneously working through a stressful change in his management team.

"I have a lot of belief in Sascha who is still very young,” Lendl said according to tennis journalist Craig Gabriel. “I think that one day he may become a great player but currently he has some off court issues that make it difficult to work in a way that is consistent with my philosophy."

Not surprising.. Ivan lendl ends coaching Zverev "I have a lot of belief in Sascha who is still very young. I think that one day he may become a great player but currently he has some off court issues that make it difficult to workin a way that is consistent with my philosophy."

— Craig Gabriel (@crosscourt1) July 25, 2019

Alexander Zverev questioned Ivan lendl's work ethic. I've been friends with Ivan for 30+ yrs, I'd question his jokes but never his work ethic. “When it comes to work ethic I am quite comfortable that my record speaks for itself” said Lendl who worked with Andy Murray a long time

— Craig Gabriel (@crosscourt1) July 25, 2019

Zverev is currently in Hamburg where he’ll contest the Hamburg European Open quarter-finals tomorrow against Serbia’s Filip Krajinovic.

The 22-year-old World No.5 made waves earlier this week when he criticized Lendl’s work ethic.

"The training is over two hours,” Zverev said. “And for half an hour he stands with his back to me and tells me about his round of golf.”