Grigor Dimitrov has revealed that he is not happy with what he has achieved thus far in his career and is always pushing to do more. The 26-year-old will compete in the Rotterdam Open, where he may come face to face with Roger Federer. The Bulgarian is upbeat about the prospect and is out to prove that he can compete on the biggest stage.

Federer needs to reach the semis in Holland to become the oldest world No 1 in tennis history. In his quest to win the title, Dimitrov will have to contend with, among others, three-time Grand Slam winner Stan Wawrinka, who is recovering from a knee problem and will compete at Rotterdam.

Dimitrov had a brilliant 2017 campaign, winning the ATP World Tour Fnals, which propelled him to a career high third in the rankings. He started the year with some strong performances in the Australian Open but fell to Kyle Edmund in the quarter-finals.

However, having realised what he is capable of, he is looking to push himself further and win tournaments which will automatically reflect on his rankings and help him go higher up the table.

"I always want to do more. I always expect more from myself, but that can also be dangerous. Regardless of how high your position in the ATP Rankings, you never lose your respect for the game. You must remember the process, what works and not take anything for granted," Dimitrov told the ATP World Tour website.

"I've learned that over the years, you're going to have ups and downs, but it's important to maintain a certain level. You can see the younger players, younger than me, are hungry!

"The dot on your back becomes a little bigger, but that's what I play tennis for: to compete, for the love of the game, to prove I can do better and sustain it on a daily basis. It really means something to me."

Unable to defend his title at last week's Diema Xtra Sofia Open due to a shoulder injury, Dimitrov is now focused on performing well in Rotterdam. He is positive about his future and his injury, which is holding up well, ahead of what is expected to be a busy schedule on tour.

"You want to compete against the top players, you want to challenge yourself. That's why I compete.

"My shoulder injury is holding up well [and] I am slowly beginning to serve a little bit faster. I have done the work in the gym. I never stop working. If I don't practise every day, I go to the gym, or go for a hike. On my days off, I like to go to the gym, just get your body moving, in a routine, a rhythm.

"I have recently felt that my body is getting to maturity and holding up well to absorb the hard work. So I am very positive about the future, I am excited to play and to compete. I know [that] if I put in the work day after day, extra effort, the results will come. The ranking then becomes automatic."