The largest annual junior competition in the United States, USTA Southern California’s Junior Sectionals kick off this week with qualifying rounds at Los Caballeros Racquet and Sports Club in Fountain Valley, and throughout Orange County.

Players between the age of 10 and 18 will compete in open singles and doubles, in addition to green ball play for youngsters 10 and under. More than 900 players are registered for the competition, which kicks off June 16-18 and continues June 20-25.

Isabella Pimentel, G12s Sportsmanship winner (right)

Among the main draw players to watch is Taylor Johnson (Girls 18s) of Redondo Beach, Calif. Johnson, who has committed to the UCLA Bruins in 2019, is the top junior player in her division throughout Southern California, and ranked second among nationwide recruits. In 2016, she was a USTA National 16s champion.

Irvine’s Maxi Duncan will compete in Girls 16s as a rising Class of 2021 recruit. Other players to watch include La Mesa’s Siem Woldeab (Boys 18s) and Ojai’s Takeyasu Sekiguchi (Boys 16s).

More than 400 matches are completed in qualifying rounds, where Thousand Oaks’ Roshan Santhosh notched a big upset of the Boys 10s top seed to earn a semifinal berth and Player of the Day honors. Camarillo’s Hana McKinney was also a Player of the Day in Girls 14s.

Saturday’s Players of the Day were Thea Frodin of Woodland Hills (Girls 10s) and Tane Rice of Studio City (Boys 10s).

Main draw play opens on Wednesday, with a total of 772 matches scheduled throughout six sites.