There was a sense of shock as Naomi Osaka announced on Monday night that she had split from her coach Sascha Bajin, just 17 days after completing back-to-back Grand Slam victories at the Australian Open.

The split was came as a surprise to the tennis world and was explained only through a brief statement from Osaka on Twitter saying she will no longer be working with him. In response, he thanked her and wished her good luck.

Bajin, a former hitting partner to Serena Williams, and Osaka had joined forced in late 2017 and the Japanese player enjoyed a breakthrough year, shooting from 72 in the world to the top of the women’s rankings winning Indian Wells and US Open in 2018.

The partnership had yielded two Grand Slams and the abrupt end surprised many. While there have been no clear reasons given why the duo have broken what is a successful partnership, there have been several reports of a falling out between the two.

Some fans pointed out that she had not named him in her speech after her win at the Australian Open. But the proof of possible acrimony was on social media as the Japanese world No 1 unfollowed her former coach on Twitter and Instagram.

Japanese media cited Osaka’s management company IMG in reporting that there had been a breakdown in the player’s relationship with the coach since the start of the year.

According to Japan’s Nikkan Sports, some practice sessions with Bajin at the Australian Open lasted just 10 minutes and she sometimes hit without him being present.

Osaka, who is scheduled to compete in Dubai next week, began sounding out potential replacements late last year, local media reported.

Interestingly, Osaka’s split with Bajin follows a pattern among the last few Grand Slam champions as both French Open champion Simona Halep and Wimbledon winner Angelique Kerber have parted ways with the coach that helped them win the Majors.

While German Kerber split with Wim Fissette, it was coach Darren Cahill who decided to move away from coaching to spend more time with his family. But the Kerber-Fissette split in October was equally contentious, over a “difference of opinion”.

Social media, meanwhile, had their own set of wild theories behind the split.

Via Reddit
Via Reddit
Via Reddit
Via Reddit

And here’s Kyrgios weighing in: