Rafael Nadal probably approves of Andre Agassi’s comments. (Josep Lago/AFP/Getty Images)

The greatest of all time debate in tennis typically revolves around two players – Roger Federer and Rafael Nadal.

Former tennis star Andre Agassi weighed in on the topic, telling Singapore’s Straits Times newspaper that Nadal, the current world No. 1, would take top billing.

“I’d put Nadal number one and Federer number two,” Agassi said (via Associated Press).

Agassi also mentioned Australia’s Rod Laver, owner of 11 majors and two calendar-year Grand Slams, when ranking the greatest players of all time, according to the Telegraph.

Federer owns 17 majors to Nadal’s 13, but has struggled against the Spaniard, who owns a 23-10 head-to-head record against his Swiss rival.

Agassi credits Nadal’s stiffer competition as a measuring point.

“Federer separated himself from the field for four years. He separated himself from [Andy] Roddick and [Lleyton] Hewitt,” the eight-time Grand Slam champion said (via the Telegraph). “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.”

Although Federer, currently ranked No. 4 in the world, has struggled against Nadal, losing five straight matches and the last six Grand Slam meetings in which they have faced each other, the 32-year-old Swiss has been the more durable of the two.

In his career, Federer has reached a record 23 consecutive Grand Slam semifinals, breaking the previous mark of 10 held by Laver and Ivan Lendl. He has also played in a record 57 Grand Slams and plans on extending his streak this month at the French Open, despite the recent birth of his twin sons.

The oft-injured Nadal has missed two majors because of an ailment since 2012 – the 2012 U.S. Open (knee tendinitis) and 2013 Australian Open (stomach virus).

The two rivals have not played each other since Federer lost in straight sets at the Australian Open in January.

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