BAYSHORE GARDENS -- He exudes a relaxed, easygoing attitude.
That's off the tennis court.
On it, Michael Mmoh emits a fiery competitiveness.
"A very calm and cool guy off the court, but definitely when it gets near competition, he's very motivated by it and doesn't shy away from it," said Glenn Weiner, one of Mmoh's coaches at IMG Academy.
Mmoh's lone opponent thus far at the 2013 Eddie Herr International Junior Tennis Championships, France's Maxime Janvier, felt Mmoh's wrath on the clay surface in the boys 18s.
Mmoh, 15, defeated Janvier 7-5, 6-2 in Monday's opening round and spent Tuesday at IMG Academy focusing on doubles play with partner Francis Tiafoe.
The duo earned a 6-4, 7-6 (3) victory over Seong Chan Hong and Chan-Yeong Oh, which allowed Mmoh to grind out points in a way that should help his singles game down the road.
"It helps a lot; there's still pressure moments in doubles," Mmoh said. "And obviously those moments help you in singles, and I've been serving really well lately. It helps your volleys, too. It's good to tune up your singles game."
Mmoh, ranked No. 19 in the world in the International Tennis Federation's Junior Rankings, rose in the rankings beginning last year with a singles title at the prestigious Orange Bowl tournament.
It came on the heels of a disappointing first-round exit in the 2012 Herr tournament.
However, Mmoh steadied himself and began a surge of solid results that has instilled confidence.
"His ability to improve his game has really impressed me," Weiner said. "He's had to make some technical changes in his game with his strokes, and he's been very quick to make those changes. And make them the right way."
But there was a bump in the road that tested Mmoh's determination and something that is common at the elite level in sports: injuries, specifically an abdominal strain that shelved Mmoh for 10 weeks during the summer and caused him to miss the U.S. Open.
Weiner said his rehab got him cleared to play the week prior to the ITF Grade 2 event in Montreal in September.
Mmoh didn't just beat the odds by playing in the tournament, but he won the boys 18 championship.
"All of the coaches at IMG told him, 'No, you haven't had enough preparation, you've hardly practiced and you may reinjure it,'" Weiner said. "And he came to us and said, 'No, it's a good opportunity to play in it and win it. I'm going.'" At that moment, was when said he saw the fire in Mmoh
Following that tournament, Mmoh's results on the ITF Junior Circuit have been glistening. He notched a semifinal appearance in the Pan American ITF event and a victory at the Osaka Mayor's Cup World Junior Tennis Championships, a Grade A tourney, in late October. The IMG student, who has grown an inch over the last year, credits the confidence in the mental game and an increase in strength, as well as utilizing a backhand as a viable weapon rather than just placing the ball back into the court, as reasons for his rankings jump
Now Mmoh turns his attention to Wednesday's match with Alexander Sendegeya, who also won in straight sets in the first round.
But it's an opponent that Mmoh is prepared for.
"I know the kid," said Mmoh, who ended last year ranked 119th. "We've been pretty close for three years now. He's good. If I play well, I should have a good chance."