Baseline is looking ahead to the new year by showcasing 21 players under 21 to watch out for in '21. To make the coveted list, players must be born in 2000 or later. 

Jannik Sinner began the 2020 season off with three out of four opening round losses. But, when the tour restarted he didn't hold back and even kicked things up a level. 

The Italian reached the third round at the ATP Masters 1000 in Rome, defeating Benoit Paire and world No. 6 Stefanos Tsitsipas along the way. In just his fourth Grand Slam main draw and his first Roland Garros appearance, he would battle his way into the quarterfinals before falling to eventual champion Rafael Nadal.

Ranking: No. 37

Age: 19 (August, 16, 2001)

Instagram: @janniksin


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What he did in 2020: Claimed his first ATP title in Sofia, taking out Alex de Minaur, Adrian Mannarino, and Vasek Pospisil. He also enjoyed his first major quarterfinal run at Roland Garros. 

Career Highlights: Despite a shortened 2020 season, Sinner sparkled by becoming the youngest ATP title-holder since 2008 when he won the title in Sofia. The 19-year-old also became the youngest Roland Garros quarterfinalist since Novak Djokovic in 2006. He ended the year with a career-high ranking at No. 37.