Two years ago, in an extraordinary burst of teenage chutzpah, Bianca Andreescu introduced herself as a major force in tennis.

In a span of 33 days, the Canadian won all 13 of her matches in Toronto and New York, beating Serena Williams in both finals. Her game consisted of thunderous groundstrokes and a sizzling serve to set them up, not-so-subtle athleticism and a sometimes startling diversity. That Serena was going for her record-tying 24th Grand Slam singles title at the US Open – supported by a rabid crowd of 24,000 – only underlined Andreescu’s accomplishment.

"I know you wanted Serena to win—I’m sorry! she said in her on-court interview – definitely not sorry. "It wasn’t easy at all."

She was only 19.

2019 Toronto highlights: Bianca Andreescu's top shots

Safe to say, the intervening two years have been hard, probably more difficult than Andreescu could have ever imagined.

A meniscus tear and the global pandemic combined to keep her off the court for 15 months. Then there was a hard quarantine in Melbourne, a foot injury that forced her to retire from the Miami final, a case of COVID-19, and the wrenching decision to pass on the Tokyo Olympics.

But now Andreescu, still only 21, finds herself in the comfort of home, playing the National Bank Open, which begins Monday in Montreal. On hand will be veteran coach Sven Groeneveld, former coach to Maria Sharapova, who Andreescu has hired for a trial period after parting ways with Sylvain Bruneau.

"He has great knowledge and I already see a lot of improvement on the court from the tennis aspect and mental aspect," Andreescu told reporters at Media Day. "So I'm feeling really confident."

She’s joined in the WTA 1000 field by five other top-10 players and, overall, 11 of the top 20. Headliners include world No.3 Aryna Sabalenka, No.6 Elina Svitolina (bronze medal in singles), No.7 Karolina Pliskova (Wimbledon finalist), and No.9 Garbine Muguruza, a two-time major champion.

Montreal Draw Preview: Andreescu, Halep return to action

"In 2019 I was the up and comer and now I'm seeded in tournaments," Andreescu said. "I have titles that I've won and I'm defending them now. So it's a whole other ballgame. On the court, I feel like I'm the same person because I'm fearless and I feel confident, at least now. The last couple of months it's been up and down but I feel much better now.

"I know practice isn't the same as matches but I really want what's happening in practice to correlate in matches."

Here are some more tantalizing storylines in Montreal:

Can Simona Halep rebound?

After 373 consecutive weeks in the Top 10, Halep will fall out Monday. That’s the eighth-longest streak in WTA history; Martina Navratilova (1,000 weeks), Stefanie Graf (625), and Gabriela Sabatini (508) are the best all-time. Serena Williams, by comparison, spent 276 straight weeks in the Top 10 and Karolina Pliskova will become the new active leader, with 236 weeks.

Halep retired in Rome with a calf tear and has not been able to play an event since. She is playing on a wildcard granted by Tennis Canada, joining Sloane Stephens, Leylah Fernandez, Rebecca Marino and Carol Zhao. Halep missed the French Open, Wimbledon and the Olympics and is eager to play in the event she won in 2016 and 2018 and reached the 2015 final.

“Can’t wait to be back!” the No.6 seed posted on Instagram.

Is Aryna Sabalenka ready to take the next step?

You could see this one coming.

Sabalenka ended the 2020 season by winning the Upper Austria Ladies Linz title and began 2021 with a title in Abu Dhabi. Before Wimbledon, she had never advanced to the quarterfinal of a major – this year she made the semifinals before falling to Karolina Pliskova.

Her biggest result? It might have been Madrid, because she stared down world No.1 Ashleigh Barty in the final and emerged with the third WTA 1000 title of her young career.

Now, can the top seed put together a nice North American summer run and perform well at the US Open, where she’s never been past the fourth round?

What’s next for Elina Svitolina?

Bronze is a traditional present for an eighth wedding anniversary, but Svitolina has always been ahead of the curve. Fifteen days after she married French star Gael Monfils, Svitolina gifted herself the bronze medal in Tokyo.

She dropped the first set to Elena Rybakina 1-6 and trailed 1-3 in the second and 1-4 in the third, but rallied to win the last five games of the match.

Yes, it’s been a whirlwind season for Svitolina but now that the wedding festivities are over, can she lock in on tennis. Her two wins over Petra Kvitova, in Miami and Stuttgart, are her only Top 10 wins so far this year.

The No.3 seed would play No.15 seed Coco Gauff in the Round of 16.

Will Karolina Pliskova catch fire?

Five years ago, the Czech Republic player won the title in Cincinnati and reached the final of the 2016 US Open, losing in three sets to Angelique Kerber. And yet, she’s never been past the quarterfinals in Canada.

Pliskova, the No.4 seed, had a terrific fortnight at Wimbledon, beating Sabalenka to reach the final, then won a second-set tiebreaker but fell to Barty in three sets.

Perhaps that success will manifest itself in Montreal, although she could face her friend and No.14 seed Karolina Muchova in the third round. Muchova has knocked her out of two Slams - 2019 Wimbledon and 2021 Australian Open. 

Photo by WTA/Jimmie48

What to expect from Garbiñe Muguruza?

The Spaniard has already won 30 matches this year and the title in Dubai, where she beat three players destined for the Top 10.

The big events, though, have been a disappointment. Muguruza lost in the first round of the French Open, the third round at Wimbledon, and fell in the quarterfinals – to Elena Rybakina – in Tokyo. This is only her fourth appearance in Canada, and her overall record is 3-3.

No.12 seed Elena Rybakina could await the No.5 seed in the Round of 16.

Another podium for Anastasia Pavlyuchenkova?

At the age of 30, Pavlyuchenkova is having a career year. She reached her first Grand Slam singles final at Roland Garros and won mixed gold with fellow Russian Andrey Rublev in Tokyo.

Pavlyuchenkova is ranked No.18, not far from her best-ever No.13, achieved a decade ago. Her best effort in Montreal is the quarters, in 2016.

How about No.10 seed Pavlyuchenkova versus Halep in the Round of 16?