TORONTO -- Daniel Nestor remembers looking at the men's singles draw before his first Rogers Cup in 1989 and thinking how exciting it would be to play John McEnroe in the second round.

Problem is, he never got there.

The Canadian doubles tennis star, then a 16-year-old wild card ranked 923rd in the world, lost handedly to No. 245 Ned Caswell of the United States in the first round, putting a quick halt to his hopes of matching up against one of the sport's top names.

"The guy I was playing in the first round was much better than I was. I don't know why I was so focused on the possibility of playing McEnroe," Nestor said with a laugh Monday in an interview with The Canadian Press.

Now 45, Nestor is a month away from retirement and gearing up for his 30th and final Rogers Cup as a professional player.

The 12-time Grand Slam winner and Olympic gold medallist has won the Rogers Cup doubles title twice -- in 2000 and 2008 in his hometown of Toronto -- and was runner-up in Montreal in 2015.

Nestor, who'll play alongside Vancouver's Vasek Pospisil this week, said his decision to retire was never set in stone. But a steady drop in the rankings -- he begins the Rogers Cup at No. 103 and hasn't won a title since 2016 -- confirmed to him that stepping away after Canada's Davis Cup tie in September was the right thing to do.

"I don't feel like I'm playing at the highest level anymore, so that's not fun," Nestor said. "Obviously, I still like competing and that kind of stuff I'll miss for sure.

"But you have to realize when your time is up, too."

Nestor's list of accomplishments includes 91 titles, more than 1,000 victories and 10 stints as World No.1. He's also played in 52 Davis Cup ties.

One of his top Rogers Cup memories came in 1992, when he won his first match in the single's main draw before running into eventual champ Andre Agassi in the second round.

"He blew me out," Nestor chuckled, recalling the 6-4, 6-4 loss to the American superstar. "It was nice to get that first win, but then I obviously got put back down to earth immediately."

Nestor won't be leaving tennis completely after the Davis Cup. He'll work with Tennis Canada next season in a variety of roles and will help out part time at TEN X, a sports facility run by former pro player Gary Muller in downtown Toronto.

While his departure represents a loss for Canadian tennis, Nestor is confident in the sport's future with youngsters like Richmond Hill, Ont., product Denis Shapovalov, 19, and Montreal's Felix Auger-Aliassime, 17, coming into their own.

There's also 26-year-old Gabriela Dabrowski of Ottawa, who's won two Grand Slams in mixed doubles already.

"This is a golden age for tennis in Canada, it's never been better," Nestor said. "We really need to keep it going. These (players) are great ambassadors at the highest level, so it's exciting times."

Nestor has been especially impressed with the drive and determination he's seen from Canada's top up-an-coming talents, something he said he lacked as a young player.

"Back then, I wasn't thinking long term, and unfortunately I think that was detrimental to me in my career in the early stages," he said. "I enjoyed tennis and I was good at it but I wasn't thinking: 'I want to be No. 1 in the world.'

"It wasn't until my mom kind of threatened me that I would have to go to university that I thought I should start getting more professional.

"That's why I'm so amazed with these younger kids, how focused they are -- that definitely wasn't me."

Shapovalov and Raonic returned that admiration when asked about Nestor earlier this week.

"He's definitely been one of my role models growing up," Shapovalov said. "It's incredible what he's been able to do in the long career that he had."

Raonic shared that sentiment, calling Nestor "significant in that sort of breakthrough for Canadian tennis."

"He's won each slam, he's got a gold medal, he's done pretty much everything you could ask of somebody in a doubles career," the 27-year-old added.

"He's definitely been someone for us to look up to."