Osaka, whose win in Melbourne took her to the world No. 1 spot for the first time, released a short statement on Twitter confirming the split. "Hey everyone, I will no longer be working together with Sascha," Osaka wrote on Monday night. "I thank him for his work and wish him all the best in the future."
Bajin responded: "Thank you Naomi I wish you nothing but the best as well. What a ride that was. Thank you for letting me be part of this."
The split comes as a major surprise given how well Osaka performed under Bajin's tutelage. After linking up at the end of 2017, Osaka enjoyed a breakthrough 12 months last year during which she won the Indian Wells title and then her first grand slam at the US Open. Having started the year ranked No. 72, Osaka finished in the world's top five. Bajin was subsequently awarded the first WTA Coach of the Year award in December.
The partnership continued to pay dividends this year, with Osaka continuing her good form by defeating Petra Kvitova to win the Australian Open in January.
Thank you Naomi ���� I wish you nothing but the best as well. What a ride that was. Thank you for letting me be part of this.
— sascha Bajin (@BigSascha) February 11, 2019
Neither player nor coach gave any indication on Monday as to why the partnership had been terminated. Bajin, who has previously worked as a hitting partner for Serena Williams, Caroline Wozniacki, Sloane Stephens, and Victoria Azarenka, will surely have no shortage of offers as he weighs up his next move.
Osaka meanwhile is scheduled to play next at the Dubai Duty Free Tennis Championships, which begins on Sunday.