If ever you needed proof that a successful junior career is not a necessity for success on the professional tour, look no further than Jannik Sinner.

The young prospect from Innichen, Italy, was never the most prolific at junior level. He started playing in ITF juniors tournaments only in 2016.

His career-high ranking as a junior was 133. He also never took part in a single junior Grand Slam. But barely two years after his junior career started, he turned pro.

Now he's a player who's already breached the Top 10 of the ATP rankings. What's more, he is seen as one of the most promising players in the world right now.

The risk he took as a junior might not have paid off for any ordinary player. Then again, Sinner is no ordinary tennis player.

He won his first ATP Challenger title aged 17 in 2019, despite having no prior wins at that level. In doing so, he became the first player born in 2001 to reach a Challenger final.

The title only served to speed up his already meteoric rise. By the second half of the year, he was playing in more ATP tour matches than he did in Challenger events.

His form reflected in the rankings too. He started the year ranked 551; he ended it ranked 78, earning him the title of ATP Newcomer of the Year. Sinner also won the ATP NextGen Finals at the end of the year.

2020 was even better for him, despite the pandemic wreaking havoc with the global tennis schedule. He reached the French Open quarterfinals and also won his maiden ATP title.

In the Sofia Open final, he beat Vasek Pospisil in a three-set match to take home the title. More titles would soon follow, with two each in 2020 and 2021.

The end of 2021 also saw him make his debut in the ATP Finals. He didn't qualify for the tournament but his ranking saw him named as one of the back-up options.

And he got his chance when compatriot Matteo Berrettini had to withdraw due to an injury. Sinner won one match but lost the other, thus failing to make the semi-finals.

Nevertheless, his consistent showings on the ATP tour and even Grand Slams have him earmarked for plenty of success in the future.

And based on his rapid rise in the tennis world, only a brave betting man would write him off.