Tennis is officially back in Flushing Meadows.

The US Open Qualifying tournament kicks off Tuesday and is free and open to the public. The tournament features 128-player fields for both the men and women contending for the final 32 spots (16 each for men and women) in the singles draws.

Contending for the coveted main draw spots on the men’s side include No. 1 seed and current world No. 52 Leonardo Mayer, who clinched his second ATP World Tour Title in July at Hamburg. A must-watch is No. 2 seed and world No. 69 Denis Shapovalov. The Canadian is in New York coming off of a magical run at the Rogers Cup in Montreal earlier this month, where he knocked out Juan Martin Del Potro and Rafael Nadal en route to the semifinals.

Both Mayer and Shapovalov were ranked outside the Top 100 at the time of the entry deadline for the US Open main draw.

On the women’s side, No. 1 seed and former WTA Top 25 player Su-Wei Hsieh will be in a field that features Belgium’s Maryna Zanevska, who holds 15 ITF Pro singles titles, as well as No. 3 seed and world No. 106 Danka Kovinic and Great Britain’s Naomi Broady.

There also are plenty of Americans competing on their home turf as well. New York natives vying for a main-draw spot include 22-year-old Jamie Loeb and Long Island’s Noah Rubin, the 2014 Wimbledon boys’ junior champion. Other Americans to keep an eye on on the men’s side include former junior standouts and ATP NextGen contenders Michael Mmoh, Reilly Opelka and Stefan Kozlov. American women to watch include No. 9 seed Kristie Ahn, No. 14 seed Nicole Gibbs and Wimbledon junior champion Claire Liu.

In addition to those playing in the qualifying, some of the biggest names in the game descend on the USTA Billie Jean King National Tennis Center the week before the main draw begins to acclimate to the courts and practice to get ready for their first-round matches. Admission to the grounds is free this week, aptly called "Fan Week," so it's the perfect time to come our to the USTA Billie Jean King National Tennis Center to catch a glimpse of your favorite pro tuning up before the tournament or watch a rising star trying to play their way into the main draw.

Qualifying action begins at 11 a.m. on Tuesday and goes through Friday. The US Open main draw takes place Aug. 28 - Sept. 10.