He is the other hope of American tennis. And he is certainly the hope of female tennis fans, though they may not know it just yet.

Tampa, Fla.-based Mardy Fish, 21, is quietly advancing his way up the tennis ladder. His gradual progress has given way, however, to a recent and sudden thrust into the spotlight.

This sandy-haired heart-throb-to-be was the only player to win a set against Roger Federer at Wimbledon in June. Then, earlier this month at the Cincinnati Tennis Master Series tournament, Mr. Fish battled his way to the finals, where he lost to his close friend Andy Roddick — the player most often billed as the future of American tennis.At the start of the U.S. Open today, Mr. Fish is ranked 24th in the world; the only Americans ranked above him are Andre Agassi and Mr. Roddick.

And what’s his name again?

That’s “Mardy with a D,” as one anonymous, energetic fan repeatedly yelled to the crowd at the Cincinnati tournament.

“It’s been quick and overwhelming,” Mr. Fish said of the attention he’s received. Relaxing in a Waldorf-Astoria suite that is heavy with locker-room smells, Mr. Fish seems anything but overwhelmed — and not at all opposed to a little more intensity.

“It would have been nice to go straight out of Juniors and then to top 30 in the world,” he said.Andy Roddick “has done some amazing things, but it just doesn’t happen like that very often.You have to go through the futures and challengers and take your bumps and bruises,” he said.

Bruises were perhaps expected in Cincinnati.”We looked at the draw and decided not to go,” said Sally Fish, the player’s mother. ” We’d call every day and ask if we should came. He’d say ‘no.'”

But Mr. Fish kept winning, all the way to the finals. While a Roddick-Fish final isn’t exactly an all-Williams sisters final, it comes close in a way. The two trained together early in their career and have a strong, competitive friendship. Mr. Fish lived with the Roddick family in 1999, while he was finishing high school.

“We were more like brothers that year,” recalled Mr. Fish.

Friends and friendly competition are a mainstay of the affable Mr. Fish’s world. In describing his game, he compares himself to his buddies.

“I would like to hit a forehand like Andy or James [Blake], but I don’t know that it will ever be like that,” he said. “My backhand is definitely better than theirs’ — and better than a lot of people’s.”

Mr. Fish also counts his aggressive net play as an asset — and something that he has in common with his coach, former ATP pro Kelly Jones. “We get along so well.We never have a problem on or off the court,” said the player.

Mr. Blake and Mr. Fish played doubles together during the Davis Cup this year. Though their match was a disappointing loss — they were up two sets then broke down — Mr. Fish looks on it as a positive experience.

“[Playing on the David Cup team] was one of my major goals in my tennis career. And to do it at such a young age was awesome, especially with a really good friend of mine,” he said. “I just loved the team aspect of it and playing for the country.”

Mr. Fish’s first match in the 2003 Open — to be played this evening— is against the Swedish Joachim Johansson, another “good friend” with whom Mr. Fish played doubles on the Juniors circuit.

“He’s big guy and a big server. I beat him in Australia, and it was a tough match,”he said.”He’s a very good player and not someone to take lightly at all.”

Friends surrounded Mr. Fish at the Waldorf (and contributed to the sporty odors). Trading barbs in the suite were doubles partner Bo Hodge, a University of Georgia tennis player who could easily play Pete Sampras in a television movie, and Kevin O’Connor, who runs the Saddlebrook Academy where Mr. Fish trains.

While guys figure largely in Mr. Fish’s life, girls don’t at the moment. This lean player with long, tapered legs says he has no girlfriend, but he does have a crush on a certain presidential niece.

“There’ll be a seat in the box on Monday night,” pipes in Mr. O’Connor. “We’ll have a little sign that says ‘Lauren Bush’!”

When the phone rings five minutes later Mr. O’Connor ribs even harder: “It’s Lauren Bush already! She’s calling you!”

The benefits of looming tennis stardom are by no means lost on this room.