Nick Kyrgios can finish the year as a world top-5 player, says Jim Courier

Nick Kyrgios, who led Australia past U.S.A in the Davis Cup quarterfinal this past weekend, can finish 2017 as a top-5 ranked player, according to tennis legend Jim Courier. Kyrgios, with 2,425 points, is currently ranked No. 16 in the ATP World Tour rankings.

The 21-year-old began the year on a sour note, suffering a second-round defeat against Andreas Seppi at the Australian Open before getting booed by his home fans at Melbourne Park for his in-game antics. After that incident, Kyrgios owned up to mental lapses and vowed to keep his emotions in check during high-pressure situations. In recent months, Kyrgios seems to have kept his word. After defeating World No. 2 Novak Djokovic on two separate occasions, the young Aussie pushed Roger Federer to the limit during last month's Miami Open semi-final at Key Biscayne, Florida. Some onlookers called his five-setter against Federer as one of the greatest non-Grand Slam matches in tennis history.

After helping Australia reach the Davis Cup semi-final Sunday, Kyrgios earned rich praise from Courier, the coach of the U.S. team. "It's all in his hands (where he goes from here). You see when he's engaged and focused and concentrating and resilient -- down a break in three different sets and found a way to win - that's a player who can and should be top five in the world by the end of the year, if he carries that through and if he's lucky with good health. It'll be exciting to watch -- it always is with him, one way or another," Courier said of Kyrgios after Australia made their first Davis Cup semi-finals since 2015, via ABC News.

Nick Kyrgios capable of winning a Grand Slam, says Courier

Australia hasn't produced a male Grand Slam champion since Pat Rafter and Lleyton Hewitt. According to Courier, Kyrgios has the needed skill set to win major tournaments. "When you see players that have so much skill and charisma start to put it together, it's exciting for everyone involved in tennis. Maybe not the guys in the locker room who have to play against him, but for everyone else involved in the sport, it's a great thing if Nick can find his potential. He's getting close to it."

Kyrgios, under the leadership of captain Lleyton Hewitt, is trying to spearhead Australia to its first Davis Cup title since 2003. “I think we can win it. I’ve beaten every other singles player. Everything needs to fall into place. But it’s not easy to beat Thommo (Jordan Thompson) over five sets. He’s got the heart of a lion," Kygrios said, via The Courier Mail, while referring to Serbia’s Novak Djokovic, France’s Lucas Poiulle and Belgium's David Goffin among other players contending for the 2017 Davis Cup title.

Nick Kyrgios and Australia will resume their pursuit of a Davis Cup crown in September when they clash against Belgium. France and Serbia will collide in the other semi-final before November's final.