Juan Martin del Potro has always been one of my favorite players, I'm sad to see him go: Stefanos Tsitsipas

World No. 4 Stefanos Tsitsipas has heaped praise on Juan Martin del Potro, calling the Argentine his favorite tennis player alongside Roger Federer. The Greek also said he was sad to see the 33-year-old in tears at the Argentina Open after what was possibly the last match of his career.

Prior to the Argentina Open, del Potro hinted that he was close to announcing his retirement. After his first-round defeat to Federico Delbonis, the former US Open champion said he would be happy even if he never got to play another match, leading many to believe he was walking away from the sport once and for all.

In a video posted by the ATP, Tsitsipas said del Potro had made a huge impact on his career.

"He was my favourite player of all-time, next to [Roger] Federer. He is someone that I grew up watching and whose style I loved. It's really sad seeing him like that. I feel for him," Tsitsipas said.

"I feel like he has left a lot in tennis. He's someone that I will definitely remember for a very long time having an impact on my career as a child," the Greek added.

A number of other players, including Andy Murray, Hubert Hurkacz and Jo-Wilfried Tsonga, also heaped praise on the former World No. 3.

Murray, who had many battles with del Potro on the biggest stages of tennis, sympathized with the Argentine's injury struggles.

"He's obviously been struggling for a very long time, I'm aware of what it's like to be in that position where you're sort of running out of options and things to rehab. Yeah it's really sad because he has had many issues throughout his career," the Brit said.

"He was always competing with the top players, always very dangerous and as a player, he had power that very few guys on tour have ever had," Murray added. "His forehand was an unbelievable shot."

Former Australian Open finalist Jo-Wilfried Tsonga said del Potro did a lot for tennis in and outside of South America.

"He's going to leave a huge legacy for South America," said the Frenchman. "He did a lot for tennis, not only in South America but also outside of it. He was one of the players who was able to beat the Big Four. He gave a lot of pleasure to the fans and he was a special player, different."

Hubert Hurkacz described the Argentine as a "great person."

"I had a chance to practice with him once or twice and his forehand, the way he hit the ball was ridiculous. He had difficult times with injuries recently and it's so tough to come back and get another injury, so it must have been very tough for him mentally as well," Hurkacz said.

"What he has achieved, what he has brought to the game, the power, the energy," he added. "Everyone liked him and supported him. Great player, great person."

Juan Martin del Potro lost in the opening round of the Argentina Open on his comeback

The Argentinian lost to Federico Delbonis in the first round of the Argentina Open

Del Potro was given a wildcard into the Argentina Open, where he lost in the opening round to sixth seed and compatriot Federico Delbonis 6-1, 6-3.

Following the match, the 33-year-old became emotional and left his headband in the middle of the net. He later said the match against Delbonis may have been the last of his career. However, he did not rule out the possibility of making a return to tennis.

"Today is a full stop but I am going to leave the window open for tennis because what I experienced tonight is unforgettable," the Argentinian said. "What is clear is, whether or not I play in Rio, I am going to take a break to let my knee recover and live without pain even if I don't play tennis. I want to have my body do what I want and not what I can."

Tsitsipas, meanwhile, is competing at the Rotterdam Open, where he is the top seed following the withdrawal of Daniil Medvedev. Tsitsipas defeated Alejandro Davidovich Fokina in his opener and will place Lloyd Harris or Ilya Ivashka next.