Madrid, Spain, 7 December 2016 |

Rafael Nadal thinks Nick Kyrgios can achieve the highest of heights in professional tennis.

The 14-time Grand Slam champion spoke glowingly about Kyrgios and another Aussie young gun, Thanasi Kokkinakis, at a recent Tommy Hilfiger promotional event in Madrid.

Nadal said the 21-year-old Kyrgios had already shown signs of what he could achieve.

“Nick Kyrgios is already at the top, a player who has an unbelievable potential,” Nadal said.

“He has [to] focus on himself, and can become world No.1 and win a Grand Slam.”

In their most recent meeting, Kyrgios pushed Nadal to 6-4 in the third set of their third-round match in Rome, on Nadal’s favoured clay.

Their career head-to-head record is tied at 1-1; Kyrgios famously won their first ever meeting in the fourth round of Wimbledon in 2014 on Centre Court.

On Kokkinakis, Nadal said: “In this new generation you will need to see how Kokkinakis will evolve.

“He suffered and injury and we don’t know how he will comeback, but he has the potential to be at the top.”