London - Andy Murray says he has only a couple of years left at the top of men's tennis, but the world number one has no intention of relaxing just yet as he sets his sights on a third Wimbledon title.
While Roger Federer and Rafael Nadal have defied the ageing process to win Grand Slams into their 30s, Murray believes that is the exception rather than the norm.
With that in mind, the 30-year-old knows he must maximise his chances of adding to his haul of three Grand Slam crowns while he is at his peak.
"My coach, Ivan Lendl, was still competitive at the top until he was about 32 but, generally, over the past 20 to 30 years, normally by early 30s is when players have struggled to stay at the top," Murray told the BBC.
"I know some of the players have been doing really well until their mid-30s recently, but that might not be the case with me.
"Maybe the next couple of years are the last few where I have a chance to compete for the majors and the biggest tournaments."
Fortunately for Murray's hopes of more silverware, he heads into the grass-court campaign back in form after his run to the French Open semi-finals ended a frustrating period marred by problems with injuries and illness.
The Scot, who has battled shingles, an elbow injury and the flu in 2017, was beaten by Stan Wawrinka in five sets on the clay at Roland Garros.
But Murray is confident he has rediscovered his rhythm in time to mount a strong defence of the Wimbledon crown he won for a second time last year.
The road to Wimbledon begins across west London at the Queen's Club next week, when Murray will be aiming to win the grass-court event for a third successive year and sixth time in total.
First up for Murray in the opening round is British number four Aljaz Bedene.
Murray beat Bedene in the second round at Queen's last year and if he wins again he will face either 2010 Queen's champion Sam Querrey or another Briton -- wild card Cameron Norrie -- in the last 16.
He is seeded to face France's Jo-Wilfried Tsonga in the quarter-finals and former US Open champion Marin Cilic in the semi-finals, with a potential final against second seed Stan Wawrinka.
Winning at Queen's would be the ideal Wimbledon preparation for Murray, but he knows he must find a way to avoid the fitness issues that have troubled him this year.
"Most of the players are travelling with physios now, spending a lot more time working in the gym to protect their bodies from the kind of pounding you give it on the court as well," he said.
"I don't know how long I'm going to be playing for any more. I want to make the most of every tournament I compete in.
"If I'm going to be away from my family, I'm not going to do that and not do my best."
Wawrinka opens his Queen's campaign against Spanish veteran Feliciano Lopez, while Milos Raonic, beaten by Murray in the Queen's and Wimbledon finals last year, starts against Australia's Thanasi Kokkinakis.
Grigor Dimitrov, the 2014 Queen's champion, is the only player other than Murray to have won the tournament in the last four years and the Bulgarian takes on Ryan Harrison of the United States in the first round.
Former Wimbledon finalist Tomas Berdych will look to pull out of his current slump against Steve Darcis.
Cilic, who won Queen's in 2013 and was runner-up a year later, opens against big-serving American John Isner.