'Emotional, inconsistent' Kyrgios can challenge for Grand Slam titles - Cash

Nick Kyrgios is far more likely to win a Grand Slam title than to become world No.1, former Wimbledon champion Pat Cash said as the 22-year-old's season-reviving run to the Cincinnati Masters final enhanced greatly the Australian's prospects of a big New York moment.

Cash has "no doubt" that rising German star and world No.6 Alexander Zverev is now regarded as the leading young player in the men's game, but there is equally no question in his mind about what Kyrgios can achieve when strong and healthy in body and mind.

"I have always said Nick will be a danger at the slams but unlikely to get to top one, two or three, as he is an emotional player and that is draining and leads to inconsistent performances,'' Cash tells ESPN.

"But he still has the potential to get to a slam semi or final -- as long as he is fresh and fit.''

Kyrgios has been neither fit not fresh for much of a turbulent season he described in Cincinnati as "a roller-coaster"; personal issues have added to the weight of frustrating and ongoing physical issues, including the left hip and right shoulder injuries in recent months that caused him to play in pain when he could play at all.

The last of three consecutive injury retirements came when he resumed in Washington from an enforced post-Wimbledon break. The Australian was booed from the court after failing to finish the second-round match against the No.106-ranked Tennys Sandgren that he trailed 3-6, 0-3. Mentally, too, Kyrgios has since admitted he was just "not there" that day in D.C.

"From where I was to here, it's just been amazing,'' an upbeat Kyrgios said his after 6-3, 7-5 loss to Grigor Dimitrov in Cincinnati, in his first ATP Masters 1000 final, on Sunday. His run of form in Ohio saw his ranking improve five places to No.18, with some practice and chill-out time with mate Jack Sock in Kansas next on his schedule.

Kyrgios said his head had been "all over the place" this year, with his grandfather Christos having passed away in late April and a reported split from girlfriend Ajla Tomljanovic in July.

"Gradually, I just feel back to where I should feel on a tennis court,'' he said. "I wasn't enjoying it at all, didn't want to be out there. External things were affecting how I was feeling ... I feel great where I am right now.''

The pain remains -- "I'm not going to act as if it's 100 percent - I'm just pushing through it" -- but the timing of his form in Cincinnati is ideal ahead of the final major of the season and Australia's Davis Cup semifinal against Belgium that follows in Brussels.

Kyrgios has won just two matches in Grand Slam tournaments this year.

The 2015 Australian Open quarterfinalist imploded in the second round at Melbourne Park after claiming the first two sets against Andreas Seppi, and he was physically underdone but emotionally cooked when he played Kevin Anderson in the second round at the French Open just weeks after his grandfather's funeral. Then, after further aggravating the hip issue with a slip on the Queen's Club grass, he estimated he was only 60-65 percent fit entering Wimbledon and lasted just two sets against Pierre-Hugues Hubert.

Signs of the injury were still apparent as he laboured through the early rounds in Cincinnati, but it may turn out to be a transformative week even though he failed to reproduce his Rafael Nadal-slaying form in the title match against an impressive Dimitrov.

Best-of-five set tennis is a different beast, and a young man who has always been in a hurry insists he is only slowly finding his way back onto the right path, but the positives were plentiful.

"I'm feeling good, I'm pretty excited for the US Open,'' said Kyrgios, whose best results at Flushing Meadows are two appearances in the third round.

"I'm just happy being out there and getting some wins again.''

Watch the US Open Live on ESPN for the first time in Australia from August 29.