Big-hitting Croat Marin Cilic remains highly motivated to try and achieve big things in the future, as he prepares to return to action after a knee injury.
Cilic, whose highest ever world ranking was number three, is preparing to face Gael Monfils at the Dubai Tennis Championships, having been forced to sit on the sidelines since losing to Roberto Bautista Agut in the last-16 of the Australian Open.
I can win one or two more Grand Slams or I may not, but I will just keep trying to play as well as I can.Marin Cilic
And Cilic, a former US Open champion and a beaten finalist at both Wimbledon and the Australian Open, is hoping to prove that he is far from finished at the top level of the sport.
He told Novosti: "Of course, I still think I can become world no.1, no matter how fierce the competition is. No.1? Why not? I will never rule that out.
"My goal this season is to reach London (ATP Finals) again and finish in the top five and I believe that's possible if I maintain the high level."
Cilic is priced at 4/5 to defeat Monfils and is 10/3 to do so in three sets, with the Frenchman 9/4 to complete a straight sets victory.
The Croat had earlier spoken of his hopes of being able to add to the Flushing Meadows title he won in 2014 and claim another Grand Slam title.
He added: "You know you are always pushing yourself to win more titles, but the bottom line is that I need to try to improve as a player and to reach the potential that I can reach.
"Who knows? I can win one or two more Grand Slams or I may not, but I will just keep trying to play as well as I can."
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