10 Biggest Prospects On The ATP Tour

Given his questionable temperament and the fact that he is still short of his 21st birthday, Nick Kyrgios should still be regarded as a prospect but if he puts all of his weapons together, he should become a top-10 player.

The Australian had been in and around main draws at Grand Slams for a while before his run to the quarter-finals at Wimbledon in 2014 but it was the manner in which he advanced through to the last eight that got tongues wagging.

He saved match points to beat Richard Gasquet before stunning Rafael Nadal in the last 16, and he showed that it was no fluke as he went on to make the same stage at the Australian Open on just his second appearance.

It is since that breakthrough where the problems have started but in 2016, he has turned a corner by winning the Marseille Open and reaching the semi-finals in both Dubai and Miami. It has enabled him to finally break into the world's top 20 but there is still far more to come from someone who can be seen as an enigma.

His ball-striking is second to none and his unconventional style leaves opponents sometimes forced to apply guesswork and those two traits could help take him to a Grand Slam title in the future.