The older teens have left Plantation after competing in the Orange Bowl International Tennis Championship, and now it’s time for the 14-unders and 12-unders to take center stage. The 50th Jr. Orange Bowl Tennis Championship begins Saturday at the University of Miami, Crandon Park Tennis Center, Biltmore Hotel and Salvadore Park.

The tournament attracts 1,325 players from 75 countries.

Twenty of the 25 top-ranked U.S. 14-under boys are entered, including No. 1 Cameron Klinger of San Jose, Calif., and No. 2 Stefan Kozlov of Pembroke Pines, who was the 12s runner-up in 2009. Kozlov learned the game from his father, Andrei, a former pro who runs a tennis academy. The 13-year-old recently moved to the U.S. Tennis Association training facility in Boca Raton, where he resides in the dorms, attends school and trains with USTA coaches.

Kozlov and his father agree that he has matured since the move.

“I am mentally stronger, a lot more stable emotionally on the court, and have cut down on my errors,” Kozlov said. “My fitness is also better. It’s a great situation at the USTA because the courts are outside my door, fitness coaches are right there, and I have kids my age I can practice against.”

He spends most weekends at home with his family.

“Stefan stopped screaming on the court and is much more professional,” Andrei Kozlov said of his son. “His attitude has improved working with the USTA coaches. I still see him a lot, so it is working very nice.”

USTA coach Nicolas Todero has been working with Kozlov since June and is impressed. “He is a pretty complete player. Even though he is still growing, he can play with the big guys because he is fast mentally and reads the game very well.”

Last week, Kozlov played up in the 16s division of the Orange Bowl International and lost to eventual champion Hyeon Chung of Korea in a three-set match that went to a third-set tiebreaker. “I learned a lot from that match about how to play tight moments.”

Kozlov’s 11-year-old brother, Boris, is entered in the 12-under division.

The Boys’ 14s field also includes top-ranked European Bogdan Borza of Romania and top-ranked South Americans Juan Pablo Ficovich of Argentina and Orlando Moraes da Luz of Brazil.

On the girls’ side, Miami’s Katerina Stewart is the top-ranked American in the 14s. Sixteen of the top 20 Americans are entered, as well as top-ranked Europeans Ana Konjuh of Croatia and Iryna Shymanovich of Belarus, and ninth-ranked South American Julieta Lara Estable of Argentina.

In the 12s, top-ranked American Alexander del Corral of Doral and No. 6 Anna Bight of Boca Raton are entered.

Alumni of the tournament include Andre Agassi, Monica Seles, Chris Evert, Jim Courier, Andy Roddick, Kim Clijsters, Justine Henin and Juan Martin del Potro. The finals for Boys and Girls 14s and Girls 12s will be at UM Dec. 23 starting at 9 a.m. The Boys 12s final is at Salvadore Park in Coral Gables on Dec. 22 at 9 a.m. Admission is free.