ALEXANDER ZVEREV is behind only Roger Federer and Rafael Nadal in the rankings - but his preparations for the US Open are a world apart.
Zverev, 21, is tipped to be a future great but he has struggled to show his potential at Grand Slam events.
The German has only once reached the quarter-finals of a major tournament - at this year’s French Open - and he crashed out of Wimbledon in round three.
Instead of taking a two-week break between the grass and hard court seasons, Zverev has instead worked tirelessly on the training ground to get in shape and finish the year with a bang.
In contrast, Nadal has spent time on his yacht and Federer with his family.
The world No 1 is not back in action until the Rogers Cup next week, with his Swiss rival returning a week later at the Cincinnati Masters.
The German was knocked out of Wimbledon in the third round (Image: GETTY)
But Zverev is competing at the Citi Open this week, where he is out to defend his crown at the start of a long hard court season.
"Washington is perfect preparation for Toronto and Cincinnati," Zverev said.
"I've done a good two weeks of training, just general stuff.
“It was like a mini off-season for me, just a lot of work trying to get ready for the hard courts.
"Us young guys, we have to get through a lot of first times.
"I've been through that stage a lot already."
Nadal has tipped Zverev to have a big future (Image: GETTY)
Meanwhile, Nadal has tipped Zverev to step into his and Federer’s shoes when they hang up their rackets.
“The young guys are coming: Zverev, [Denis] Shapovalov,” Nadal said.
“I’m not going to name them all, but there are many out there right now who I think are particularly special, and they are obviously going to replace us.”