Asmuss Quietly Makes a Racket on Court : Girls’ tennis: Mater Dei’s No. 1 singles player, who has a 99-3 record in two seasons, seeks a third Angelus League title.

Three teen-age boys and a girl entered one of the courts at the Costa Mesa Tennis Club for a friendly doubles practice match.

They laughed and joked as the shots sailed back and forth. Two of the boys, in particular, were glad for the relaxed atmosphere. They weren’t facing Erika Asmuss in a real match.

Asmuss, the No. 1 singles player at Mater Dei, commands serious respect from opponents. In her two seasons on the Monarch girls’ team, she is 99-3 in regular-season play and twice has won the Angelus League singles title.

That record and a reputation as a fierce competitor make Asmuss an intimidating force on the court.

“Most of the guys at Mater Dei are scared of (playing) her,” said David Thomas, a doubles player on the Monarch boys’ team and one of those in the practice match. “She’s really consistent. . . . She doesn’t make many mistakes. If she makes one a game, that’s a lot for her.”

Not true, said Eric Widera, also a doubles player at Mater Dei.

“One mistake a match, “ he said.

They might have something there. This season, Asmuss is 12-0 and has lost only two games, both in the Monarchs’ 10-8 victory Wednesday over Fountain Valley. And she almost kept her unbeaten streak alive against the Barons despite being ill.

“She had a fever and probably shouldn’t have been playing,” Coach Sharon Kennedy said. “She’s relentless. She never gives up in a match.”

Playing at less than her full physical strength is nothing new for the 16-year-old junior. She’s had to endure a series of nagging injuries--a muscle tear in a thigh; knee, elbow, wrist and shoulder problems--that made her consider quitting a few times. But that would have been against her nature, so she stuck it out.

“Two years ago, I had tendinitis in my shoulder,” said Asmuss, who is ranked 12th by the U.S. Tennis Assn. in the 16-and-under division in Southern California. “My doctor told me I should quit or at least lay off for a while--or have surgery. I took off about two months and (the tendinitis) went away. Earlier this year, I had tennis elbow.”

The injuries concerned her mother, Kuniko Asmuss, to the point that she asked Erika to give up competitive tennis. Her parents also thought the demands of being on Mater Dei’s team and her schoolwork would be too much pressure. But so far she’s handled both challenges. She’s practically unbeatable on the court and carries a 3.8 grade-point average.

“I worry about her health. You name it (injury), she’s had it,” her mother said. “School is getting tough, so we wanted her to quit and just have a normal high school life.”

Asmuss wasn’t sure she wanted to invest so much time in the sport when she started playing five years ago.

“Some friends of mine played casually on the weekends and asked me if I wanted to play, so I said, ‘Sure,’ ” Asmuss said. “In the beginning I hated it because it would take too much practice to get good at it. At first I said, ‘This is not the sport for me.’ But then I went back to it because my friends were into it.”

And perhaps because she grew up in a tennis environment. Her West German-born father, Manfred Asmuss, competed in amateur tournaments in Europe, and her mother picked up the sport after coming to the United States from her native Osaka, Japan. Her parents met when they were college students in Pennsylvania and married soon after. Erika was born in Bethlehem, Pa., and the family moved to California in 1973.

“We stayed here (United States) because this is mutual ground, so to speak,” said Kuniko Asmuss, laughing.

Now other common ground is the tennis court, where they watch their daughter play. They have seen her develop into a formidable player, one that Kennedy says is not only a tough competitor but also a class act.

“She’s very open to learning new things. That’s part of what makes her such a great player. She’s constantly improving,” Kennedy said. “And she’s also a plain, very nice girl, which is kind of unusual, because so many tennis players seem to have an attitude.”

The only noise you’ll hear from Asmuss’ direction is the thump of the ball against the racket after one of her strong, two-handed backhands. The little talking she does off the court is when she mentions some of her goals for the season, though she talks more from confidence than cockiness.

“I want to be undefeated this season,” she said. “And hopefully win the Angelus League singles title.”