Brian Baker is not among the collection of highly ranked players and Grand Slam champions playing tennis at the Rio de Janeiro Olympics.

Baker was supposed to be one of those stars, though — or at least appeared destined for big things as an up-and-coming teen who reached No. 2 in the world junior rankings and was the French Open boys' runner-up in 2003.

"He's a great ball-striker. Always has been. Still is," said Jay Berger, who will coach Baker and the rest of the U.S. men's tennis team in Rio, where competition begins on the hard courts Saturday. "He has an incredible understanding of the game and where the ball is going."

Ah, but Baker's body has been the problem. Repeatedly. To the tune of 11 operations. Procedures on both hips. His right elbow. His back. Surgery for a sports hernia. Four repairs of his right knee.

Instead of giving up, he has mounted comeback after comeback after comeback. The latest return happened at the Australian Open in January, when he played his first match in nearly 2½ years after recovering from a torn meniscus in his right knee.

"It's an incredible story. It's unfortunate everything he's been through. We all say that if he had stayed healthy, easily he'd be a top-20 player, if not top-10," U.S. teammate Denis Kudla said. "It's just that his body hasn't really done him any favors. But it's going to be a special moment for him, knowing maybe he never got the chance to represent his country, even though he probably felt he could have been doing it for the last 10 years."

Baker will play 107th-ranked Yuichi Sugita of Japan on Saturday, when others in first-round action include major champions Venus Williams, Serbia's Ana Ivanovic and Croatia's Marin Cilic in singles, and Serbia's Novak Djokovic in doubles.

It's natural to wonder whether Baker ponders what might have been.

"I mean, you probably think about it, but at the same time, I can't do anything about it. I did get injuries," Baker said.

"I would like to have thought that I would have had a pretty successful career and done well. But I'm not going to say, like, 'Oh, yeah, I would have been top 10,'" he continued. "But sure, I would hope that I would be able to have a successful career, be a top-30 guy, year-in and year-out. But who knows?"

That, indeed, is the question when it comes to Baker, a 31-year-old who reached a career-high of No. 52 in the ATP rankings in 2012, and is currently No. 334.

So how did a guy that far down get a spot on the four-man U.S. singles roster for the 64-player draw in Brazil?

First of all, it helped that two Americans, John Isner and Sam Querrey, chose to skip the Rio Games. And Baker took advantage of a rule that allows injured players to use what's known as a "protected ranking" to enter nine tournaments of their choosing when they return.

To those who think Baker shouldn't be in the field, Isner offered this answer: "Look, it's all within the rules. ... So good on him for getting into the Olympics and earning this spot — and hopefully he can do something with it."

While tennis players in Rio will earn neither prize money nor rankings points, Baker decided this was too rare an opportunity to let pass.

"Obviously you want to be able to utilize your 'protected ranking' to try to help get your ranking back up," said Baker, who spent time during his most recent rehab stint finishing his degree in general business with a finance concentration from Belmont University in Nashville, Tennessee, where he also coached tennis. "But I think the Olympics is a different animal."

He recalls watching Andre Agassi win a gold medal at the 1996 Atlanta Games.

"There's not many things like the Olympics. It's a different thing. You're not there just playing for yourself; you're playing for your country," Baker said. "It's going to be a once-in-a-lifetime opportunity."

One worth waiting for.

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