Novak Djokovic's sad theory backed up by fellow star - 'I don't see that now'

Grigor Dimitrov has echoed 's theory about seeing their rivals retire.

recently and Rafael Nadal will be the next star to

Djokovic previously admitted that And Dimitrov admitted he felt the same as he claimed the new generation didn't have fun like they did.

This year has been a big one for high-profile retirements in tennis. Andy Murray and Angelique Kerber ended their careers at the Olympics, Thiem said farewell at last week's Vienna Open and Nadal will bow out at the Davis Cup Finals.

It's not just their fans who have been rocked by their goodbyes. Djokovic recently said he was "overwhelmed" seeing his Big Four rivals enter retirement.

Dimitrov has now explained how tough it's been to see Thiem and Nadal reach the ends of their respective careers.

"It's sad. I saw Dominic a couple of days ago - he was in Vienna as well. I cannot help but think about that as well," the 33-year-old told .

"Of course, everything has a beginning and an end, but seeing competitors that you grew up with and seeing these guys that are pushing you to do better, it takes a little piece away from you; that's just how it is."

While some of his contemporaries are slowing down, Dimitrov has enjoyed a resurgence over the last year. He picked up the Brisbane International title in January and returned to the top 10 after reaching the Miami Open final.

The Bulgarian has a good relationship with younger colleagues like Carlos Alcaraz. But he believes there isn't the same camaraderie among the new generation.

Dimitrov added: "I have respect for the new generation and everyone that is playing out there, but off the court it was a lot of fun; we were always poking fun at each other and I don't see that now.

"I miss that healthy competitiveness, but I have nothing but respect for these players."

The world No. 9 isn't the only veteran who misses his old rivals. Djokovic will be the last active member of the Big Four when Nadal retires next month and he's struggling to adjust to life without his biggest competitors.

"Yeah, I mean, we knew that that moment is coming sooner than later but it's still a shock when it came officially," he said in the wake of Nadal's announcement.

"Also for Roger a few years ago when he announced retirement and Andy as well this year. I mean it's a bit overwhelming for me to be honest. I don't know what to make out of it.

"I still enjoy competing but part of me left with them, big part of me."