LAKE BALBOA -- When Marti Sementelli was 5 years old, she started playing baseball in the Van Nuys/Sherman Oaks Parks and Recreation league. When she was 7, she started pitching in Little League.

On Saturday, the 18-year-old Birmingham senior will start for her high school baseball team against San Marcos from Santa Barbara.

She will be going up against senior Ghazaleh Sailors in what is believed to be the first matchup of girl starters in a baseball game in California high school history.

There were 1,012 girls playing baseball on high school teams in the United States in 2008, according to the National Federation of State High School Associations. California had the most girls playing baseball with 385, but none of them faced each other as opposing pitchers.

“I don’t think anyone’s ever seen something like that before,” Sementelli said.

Sementelli pitched 25 innings and won one game as a junior for Birmingham. Sailors is making her varsity debut. Both girls are making their first starts of the season.

While the girls play for high school teams that are separated by hundreds of miles, they are no strangers. Sementelli and Sailors were teammates on the United States national team that won the bronze medal in the World Cup of Women’s Baseball in Venezuela over the summer.

Baseball has been a part of Sementelli’s life since she was a toddler. She grew up with grass and mounds on the infield as opposed to dirt and circles as is the custom in softball.

For Sementelli, softball was never an option. She doesn’t know how to play softball, not that it would be that difficult for her to pick up. She’s just never played softball. Baseball is more her speed and style.

“My dad taught me when I was little,” Sementelli said. “I never, ever thought about playing softball. My dad played in high school. He taught me everything about baseball.”

Matt Mowry, the Birmingham baseball coach, said Sementelli is treated no different than any other player on the baseball team. Not by the coaches and especially not by her teammates.

“The key is, she doesn’t expect anything different,” Mowry said. “It’s nothing new to her. She’s been around it her whole life.”

Sementelli isn’t the first girl Mowry has coached on the Birmingham baseball team. Andy Parsons played for Birmingham in 1996 and 1997 when Mowry was an assistant coach on the baseball team. She was a second baseman who could turn a double play as well as anyone, Mowry said.

In the 17 years Mowry has coached baseball at Birmingham, Sementelli and Parsons are the only two girls to make the varsity team. By comparison, there were two girls on the Birmingham football team in the fall.

Attracting national attention is nothing new to Sementelli. She was featured in a New York Times story on girls who play baseball two years ago when she was on the junior varsity team at Burbank High School. She was in a Nike television commercial, donning a backward Boston Red Sox cap, when she was in junior high.

Sailors is not so used to the limelight. She was 0-2 on the junior varsity baseball team at San Marcos in her junior season.

When it comes to pitching ability, Sementelli said she and Sailors are comparable.

“She’s practically the same as me,” Sementelli said. “It’ll be an even playing field. She throws about the same speed as I do. It will be a pretty good battle pitching against each other. I’m looking forward to the game.”