SINGAPORE: Andre Agassi has picked Rafael Nadal ahead of Grand Slam record-holder Roger Federer when asked to choose the best player in tennis history, a report said on Thursday.

The American, putting a new slant on one of the sport's great debates, said he prefers Nadal because the Spaniard has thrived in an ultra-competitive “golden age of tennis”.

“I'd put Nadal number one, Federer number two,” the eight-time Grand Slam-winner told Singapore's Straits Times in an interview.

“Federer separated himself from the field for four years. He separated himself from (Andy) Roddick and (Lleyton) Hewitt,” Agassi added.

“Nadal had to deal with Federer, (Novak) Djokovic, (Andy) Murray in the golden age of tennis. He has done what he has done and he's not done yet.”Conventional wisdom ranks Federer ahead of Nadal, as the Swiss holds a record 17 Grand Slam titles against 13 for the current world number one.

But Nadal has a convincing 23-10 head-to-head record against Federer and is one Australian Open victory away from becoming only the third man to win all four Grand Slam titles twice.

“He has won multiple (majors), every single one (more than once) except the Australian Open -- and give him another year on that,” Agassi said.

“It's just remarkable to me what he has done, and he has done it all during Federer's prime.”

Agassi added that he did not discount Australia's Rod Laver, two-time winner of the calendar-year Grand Slam, when rating the greatest player of all time.

And he confirmed he would play in the Singapore leg of the inaugural International Premier Tennis League (IPTL) after the dates were rejigged to avoid Thanksgiving -- as long as the event goes ahead.

“It seems like it's all happening. I just can't make any promises I can't control. What I can't control (is) if (the event) really exists or not,” he said.

“But if it's happening, I'm absolutely going to be there and I will spend time leading up (to the event) playing.”

Agassi had initially balked at playing on Thanksgiving weekend, but Singapore is now due to host the IPTL from December 2-4, according to the report.

Despite a player draft in March, some details of the made-for-TV, four-stop competition remain murky.