Visualization and other mental exercises are helping US Open champion Bianca Andreescu compensate for limited training opportunities during the COVID-19 lockdown.

Currently ranked No 6 in the world, the big-hitting teenager won her first WTA title at Indian Wells last year, then beat Serena Williams in the finals at Toronto and again at the US Open in Flushing Meadows, New York, to become the first Canadian－male or female－to win a Grand Slam crown.

Andreescu sustained a knee injury at last October's WTA Finals in Shanghai that derailed her climb up the rankings, and she was still recovering when the season was halted in mid-March due to the coronavirus pandemic.

"I have only just got back to working out," Andreescu, who turns 20 next month, told Eurosport's Tennis Legends podcast on the weekend.

"It is tough here in Toronto because they even closed all the parks. Nobody can play any tennis, basketball or even just sit on a bench. But I have been working out in my mind as much as I can. It's a very powerful tool that I like to use."

The knee injury forced Andreescu to miss the Australian Open, the year's first major, which went ahead as scheduled in January. French Open organizers shifted this month's clay-court major at Roland Garros to September, while Wimbledon has been canceled.

The fate of the US Open will be decided next month.

"I don't know what the future has in store, but I'm going to give it my best," said Andreescu, who became an international sensation and climbed to world No 4 with her back-to-back triumphs over Williams last year.

"It's tough when you don't have a goal in mind, like a tournament to work for. But if I do have the privilege to start playing again, I would so love to because I was already off for like three months and I was kind of ready to return to play right when all of this started. It was terrible timing.

"I don't like losing, so we'll see. That's definitely the goal, to become world No 1, as every other Grand Slam is as well. I want to reach that number one spot. I really do."

Andreescu and compatriot Felix Auger-Aliassime took time on the podcast to thank Tennis Canada for investing in developing a platform for the future. Along with Denis Shapovalov, Milos Raonic and Eugenie Bouchard, they represent the next generation of Canadian challengers for international glory.

"Taking people from all over the country, getting out of their comfort zone as a federation, is finally paying results," Andreescu said. "They made some key changes a few years ago that have made a big difference."

In an interview with SportsNet Canada last month, Andreescu said her biggest disappointment during the lockdown was seeing this summer's Tokyo Olympics placed on hold.

"I've dreamed of playing in the Olympics since I was like 13 years old, so having the Games canceled after all the anticipation was pretty heartbreaking," she said.

"But at the end of the day, the health of the athletes and fans and workers at the Olympics is the most important thing, so I'm sure they made the right decision.

"It's all about perspective. But hopefully now we will be able to focus on Tokyo 2021. Let's make that happen at least."