Up-and-coming Canadian Gabriel Diallo constantly learning during rapid ascent

Gabriel Diallo's learned many lessons on his journey to becoming a professional tennis player - including in moments he least expected.

Diallo was 14 when he competed in a small event that pit a group of Canadian junior players against an American squad. The Montreal native recalls being "absolutely smoked" in a doubles match, though neither he nor his partner took the loss particularly hard.

Following the lopsided result, Diallo prepared to join his teammates, who were laughing and enjoying each other's company, when his coach, Bruno Agostinelli, asked where he was going.

When Diallo said he was going for lunch, the late Kentucky standout told him to do suicides instead.

Diallo proceeded to run nonstop for about 25-to-30 minutes. Only when he followed in Agostinelli's footsteps and joined the Wildcats' tennis program a few years later did he learn more about his former mentor and the reasons for his actions that particular day.

"At the time, we were a little bit rattled," Diallo told theScore ahead of his main-draw debut at this week's National Bank Open in Toronto. "But now, I think about those stories and understand it's the self-discipline that he had as a player and tried to impose on us.

"When you speak with some of the players that he worked with on a consistent basis - like Liam (Draxl), Joshua Lapadat, Denis Shapovalov - they can attest to that. I think that's something that helped us a lot."

Diallo admits he was a bit all over the place when he arrived on campus in 2019. It showed in his play; he'd immediately follow a solid stretch of results with an equally poor string of showings. He had a losing record in both singles and doubles in his debut college season.

The COVID-19 pandemic cut Diallo's freshman year short, but he saw it as a blessing in disguise. The time off allowed him to reflect. He started to take school more seriously, paid attention to his nutrition, and implemented a proper pre- and post-match routine.

All of that paid dividends. Diallo went 57-16 in singles play over the next two years in Lexington, earning Intercollegiate Tennis Association All-American honors twice and a pair of All-SEC first-team selections. The big-serving righty peaked at No. 2 in the NCAA rankings.

Diallo clinched Kentucky's first Final Four berth with a three-set win against top-seeded TCU and advanced to the Elite Eight at the NCAA singles championship in his junior 2021-22 season.

That summer, Diallo returned home to work with veteran Canadian coach Martin Laurendeau. While the two collaborated in the past, this marked their first full training block as a team, along with fellow Tennis Canada coach Vincent Millot.

Laurendeau's helped several prospects transition to the pros. He notably served as Canada's Davis Cup captain for 13 years before relinquishing the position to focus on being Shapovalov's full-time coach.

Under Laurendeau's tutelage, Shapovalov had a breakout 2017. The electric shotmaker became the youngest ATP 1000 semifinalist, upsetting former Grand Slam champs Rafael Nadal and Juan Martin del Potro during his run on home soil at that year's National Bank Open. He cracked the ATP's top 50, climbing 200 spots to do so.

After seeing what Laurendeau did for Shapo, Diallo believes the coach is the right person to take his own game to the next level.

"He went through the steps that I went through," Diallo said. "As a player, he went to college. He went to Pepperdine for four years. Played with some of the best players on the planet. Even though I was struggling a little bit at the beginning, I liked his philosophy to try and get to the net, and play a little bit closer to the baseline."

Laurendeau's more aggressive approach complemented the tools Diallo already had. Although the 6-foot-8 Canadian is quite mobile for his height, Diallo's well aware he isn't a grinder. Instead, he prefers to shorten rallies and impose his power on the opposition.

The formula translated into success during the second half of the 2022 season, as Diallo embarked on his first extended run of matches on the pro circuit.

In June, Diallo triumphed at the ITF M25 tournament in East Lansing, Michigan, defeating former Wimbledon junior singles champion Noah Rubin en route to his first crown on the third-tier tour.

Two months later, Diallo made his ATP Tour debut as a wild card at the National Bank Open in Montreal and stunned then-World No. 62 James Duckworth in straight sets in the first round of qualifying. Despite subsequently falling short of the main draw, he built on that victory a few weeks later at the Granby Challenger.

Capitalizing on another wild card from Tennis Canada, Diallo took out up-and-coming Chinese teenager Juncheng Shang for his maiden title on the second-tier men's circuit. He became the youngest Canadian to capture a Challenger event since Felix Auger-Aliassime did so in 2018.

Diallo returned to Kentucky after claiming the biggest trophy of his young career and played the odd Challenger tournament in North America during the fall semester.

He kept rolling on the court while writing exams. In September, he earned his first call-up to Canada's Davis Cup team and was on the roster again later that year when it won the prestigious competition for the first time.

The 21-year-old ended 2022 with a finals appearance at the Fairfield Challenger and a semifinal run at the Calgary Challenger. A month after Calgary, he officially forwent his final year of college eligibility to go pro full time.

Diallo can't emphasize enough how helpful his time in Kentucky was. He learned how to manage his emotions over a whole season and competed in front of some hostile crowds. Consistent match play was an added benefit - there's no guarantee he would've competed regularly had he jumped straight to the pros after juniors.

Diallo pointed to Ben Shelton, who he beat at Fairfield and competed against in the SEC, as further evidence that a few extra years in the college system doesn't hurt. Shelton, a Florida product, reached the 2023 Australian Open quarterfinal less than a year after winning the NCAA singles championship, and his early success has driven Diallo.

"It was extremely motivating because we kind of had the same path - and not just him. But guys like Chris Eubanks, (John) Isner, and Kevin Anderson (all) went through the college route," Diallo said. "It's been going on for a long time, and people just didn't realize. But now, I think there's more light being put on college programs, and hopefully, more kids can go through that and then realize that it's also a great path."

Diallo heads into his first-round matchup against Dan Evans (scheduled Monday at 11 a.m. ET) at this week's National Bank Open ranked 140th. He opened 2022 ranked 991st and 2023 ranked 227th. His first full season on the men's circuit has had its share of ups and downs - as expected for any rookie.

Diallo's a combined 21-11 this year on the lower-level Challenger and ITF Tour, including a victory over then-World No. 25 Evans in only his second career tilt on grass. However, the Canadian's been ousted in qualifying in each of the majors and continues to seek his inaugural ATP tour-level main-draw win.

The youngster's education continues: Having played exclusively on hard courts until this past spring, Diallo's encounters on clay and grass have challenged him to adapt and develop other skills. That problem-solving element of the sport is what initially drew Diallo to tennis as a kid, and it'll be a huge factor in how far he'll advance in the sport.

"You have to learn how to compete and how to manage matches," Diallo said. "How to win when you're not playing your best. No one's gonna help you. You don't have teammates.

"When you're playing the match, you have to figure it out yourself. I think that's something that I liked. Obviously, sometimes you don't figure it out and you lose. But that's something that I enjoy."