Tennis: 'Motivated' Nick Kyrgios champing at the bit ahead of Davis Cup quarter-finals

AUSTRALIA (REUTERS) - Nick Kyrgios is relishing being in the "best" mental shape of his career and credited the camaraderie of Australia's Davis Cup team for his ominous form during the United States' hard court swing.

The world No. 16 pushed Roger Federer to the wall in a classic Miami Open semi-final on Friday and beat world No. 2 Novak Djokovic twice in succession in the past month.

The emotional 21-year-old now carries Australia's hopes of reaching the Davis Cup semi-finals when the hosts play the United States in Brisbane this weekend.

Having long felt ambivalent towards the sport and admitted to struggling for motivation, Kyrgios has brought a new intensity to training and a stronger focus on court.

"I think my level's always been there but I think where I'm at mentally at the moment, I'm just competing for every point and playing hard and I haven't really had that mindset before," Kyrgios told reporters in Brisbane on Tuesday.

"I'm feeling motivated and I want to get out there more. I want to compete and I want to play.

"I'm probably in the best place I've ever been in."

It was little more than two months ago that Kyrgios bowed out of the Australian Open in acrimony, jeered by home spectators after giving up a two-set lead in defeat to Italian Andreas Seppi.

But weeks later, he returned to play in the first round of the Davis Cup in Melbourne, playing a pivotal role in the 4-1 defeat of Czech Republic.

Kyrgios' commitment to the team tournament has not always been so wholehearted.

He was reported to have wanted out during a singles rubber defeat during the 2015 quarter-final against Kazakhstan in Darwin and withdrew from last year's first-round tie against the US in Melbourne, citing "illness".

That withdrawal prompted criticism from team-mate Bernard Tomic, who publicly upbraided him for the decision to pull out.

Kyrgios returned to the fold for the world group play-off win over Slovakia and has been a fixture since, while Australia's No. 2 Tomic has opted out.

Kyrgios said the win over Czech Republic had worked wonders for his motivation.

"I think the last Davis Cup tie helped me a lot. Ever since then I've been in a good mental space," he said.

"I prefer the team environment, I love being around these guys, I love training with them and I love being on the sidelines watching them compete.

"I've been wanting to play and they've all been supporting me. It's good to know these guys have my back and I think it's just the chemistry.

"I feel like I'm playing well, and I've got a really good opportunity now to battle against the US."