After Nick Kyrgios’ huge upset victory over then World No. 1 Rafael Nadal at the 2014 Wimbledon Championships, tennis legend John McEnroe was left impressed by the 19-year-old Australian’s effort calling him as the next big thing in the sport. McEnroe emphasised the same point on Saturday saying that Kyrgios will be a “top five [player] in the world for sure”

“The sky is the limit for Nick. He has the potential to be an incredible shining star,” McEnroe stated via The Daily Telegraph. “When I saw him at Wimbledon, when he made his breakthrough, I thought this guy is going to be top five in the world for sure.”

McEnroe is referring to the Kyrgios’ upset of Nadal at the All-England Club earlier in 2014 when the Australian beat the Spaniard in just four hard-fought sets, 7-6 (5), 5-7, 7-6 (5), 6-3.

“If I had to pick one guy in the world, [someone] under 22 who has the greatest chance of making the biggest impact, it’s Nick,” McEnroe continued in the same article. “The improvement he made from when I saw him a couple of years ago to what I saw playing Nadal … I thought, ‘Oh my God, this guy has made an incredible improvement.”

Kyrgios’ improvement is being noticed not only by McEnroe and the fans but the tennis pundits as well. In an article at the ATP’s official website, Kyrgios was listed as one of the nominees for their Most Improved Player of the Year for 2014.

“I am deeply honoured to be nominated for the ATP Most Improved Player award,” Kyrgios said in the ATP article. “To be recognised alongside such great players who have won this award before is special and to be nominated alongside Roberto, Marin and Kei this year is hugely humbling. I've had a good year in 2014 and I look forward to improving further in 2015.”

The 26-year-old Bautista Agut of Spain won the most improved player award but Kyrgios remains one of the rising stars in the sport especially that he’s just 19 years old. McEnroe called Kyrgios’ upside as tremendous and incredible.

McEnroe wasn’t done hyping the teenager from Canberra, Australia. The tennis legend also added that Kyrgios’ personality and fire is something that he likes very much and something “extremely important” in the sport of tennis.