Canadian number one Milos Raonic has insisted that he has the potential to challenge for Grand Slam titles in the future.
"The thing is, I don't know what the time frame will be," said Raonic. "But it's going to happen, I feel like I'm a lot closer.
"But you can't place time on confidence, on belief, on getting through a few tough matches. But I know as far as ability goes, as far as skill sets go, I'm getting closer and closer.
"I've done a lot of good work, I feel like I'm playing much more improved [tennis] than I was, just really getting match-ready. When that happens, hopefully sooner than later, I think I'll be taking good care of myself."
Raonic, who is currently ranked 15th in the world, won two ATP singles titles in 2012.