Nick Kyrgios is no slouch. At just 22, he's already won three titles and defeated members of the Big 4 on numerous occasions, most recently beating Novak Djokovic in the BNP Paribas Open in March. However, with 20-year-old Alexander Zverev winning his first ATP Master's title in Rome (the first player born in the 1990s to do so), Kyrgios has admitted to being a little green with envy.

"[Zverev] has been playing great tennis, he has a huge future ahead," the Australian said. "I actually envy him in a way. He does things in all the right ways and he's very professional. That's obviously something that I don't tick the box there so he has a great career ahead of him."

Kyrgios hasn't added to his ATP tally this season or even reached a final. But he made a spirited run to the Miami semifinals, and will look to gained momentum in Paris after being knocked out of Lyon in his opening round this week.

In standard Kyrgios fashion, he still couldn't help himself from taking a little jab at Zverev.

"You know, as it stands at the moment, I've got the winning record," Kyrgios said. "So I'm sure I'll get the chance to play him a lot more times."