Dominic Thiem "didn't have the courage" to tell me we're no longer working together, I was loyal for 6 years: Fitness coach Alex Stober

Fitness trainer Alex Stober confirmed on Thursday that he is no longer working with Dominic Thiem. The Austrian has seemingly dropped Stober to make way for "neo-fitness" trainer Jez Green, who has worked with Andy Murray and Alexander Zverev in the past.

Thiem has been tight-lipped about the coaching change, but reports suggest he took the decision after signing with Spanish sports management agency Kosmos.

But Alex Stober recently spoke in disparaging terms about the end of his partnership with Dominic Thiem, highlighting how he wasn't given any warning about the change.

"I was absolutely loyal to Dominic for six years," Stober was quoted as saying by tennisnet. "And then he doesn't even have the courage to tell me that we are no longer working together."

Stober also revealed that the separation is set in stone despite Thiem claiming that he was still a part of his team in an interview earlier this month.

The change from Alex Stober to Jez Green is one of many backroom staff changes made by Dominic Thiem recently. The Austrian also parted ways with manager Herwig Straka prior to joining hands with Kosmos.

Thiem had a public falling out with long-term coach Gunter Bresnik in early 2019. Bresnik famously sued the 28-year-old for a whopping €450,000, before agreeing to settle the matter in private.

Dominic Thiem now works with former Olympic medalist Nicolas Massu, who has been coaching the Austrian for over two years. Under Massu's tutelage, Thiem won his first Grand Slam title (US Open 2020) and first Masters 1000 title (Indian Wells 2019). He has made four other big finals during this partnership - Roland Garros 2019, ATP Finals 2019, Australian Open 2020 and ATP Finals 2020.

"I want to be stronger than ever in Australia" - Dominic Thiem on 2022 comeback

Dominic Thiem training prior to the 2020 Nitto ATP Finals

Dominic Thiem had to end his 2021 season early after sustaining a wrist injury at the ATP 250 event in Mallorca. The Austrian's season had already been derailed by physical and mental issues, with a win-loss record of 9-9 for the year.

Thiem recently revealed that he had attempted to rush his recovery in order to come back quickly, which may have caused further problems. He also claimed he has been working hard under the supervision of Jez Green, and that he looks forward to return to the tour at the 2022 Australian Open.

"I wanted too much too early on the first attempt," Thiem was quoted as saying by Heute. "I want to be stronger than ever in Australia."

The Austrian missed his first Major in more than six years at Wimbledon, following which he also skipped his title defences at the US Open and Indian Wells. Thiem is likely to be out of the top 10 when he returns to the tour.