They'll show Bob Bowman, not just Phelps' coach, but also a surrogate father in many respects. He'll bark and he'll calculate, and when this hunt for gold is complete, he'll deserve much of the credit.
But when you see Debbie, pay special attention to a couple of faces around her in the stands. Cheering every race, shedding tears with remarkable frequency, are sisters Hilary and Whitney. Put simply, not only would Phelps have not found the sport without them, but he also wouldn't be the person he is.
Not only does Phelps have more gold medals hanging in his closet than the president has neckties, but he's also about as well-adjusted as you can reasonably expect from a confident, elite performer, a champion without peer.
You want to point to his physical attributes, to his mental toughness, to his training and his dedication. Or you can simply point to his genes and to his sisters.
"A swimmer's path isn't always an Olympics path," Debbie says. "There are many different paths to take. Hilary was a DivisionI swimmer. Whitney was swimming at age 14 in Rome. And Michael is … well, he's Michael."
Hilary, 30, hit the water first, taking up the sport in 1985, the same summer her baby brother was born. She remembers the instant she threw her childhood into the pool. "I swam in a meet at the end of the year," she says. "I ended up getting a third-place trophy, and I said to my mom, 'I want a bigger trophy.' 'Well, honey, these kids swim year-round, and they practice all the time.' That was it."
Whitney, 28, would follow her to the pool, and it was only natural that when Michael was old enough, he would, too.
"He was literally raised on the pool deck," Hilary says. "Because we were swimming since he was able to walk, he was at meets all the time. He kind of grew into it."
Carrying the golden Phelps gene, Hilary and Whitney found their own success in the water. The eldest eventually swam at the University of Richmond, and Whitney nearly became the first Phelps to compete in the Olympics.
"Michael really looked up to Whitney and Hilary," says Tom Himes, who coached all three Phelps children at North Baltimore Aquatic Club. "They did a lot of watching after Michael, too. Certainly, as far as swimming goes, Michael didn't know anything other than being intensely focused on swimming. If his sisters were lackadaisical, maybe he wouldn't be doing what he's doing. But he never knew any other way to do it."
Himes says Whitney was actually better than Michael when she was younger. "She could train like no other girl I've ever seen," he says.
But Whitney was also pained by a bad back from a young age. Leading up to the Olympic trials in 1996, she was actually favored in the 200-meter butterfly but was in too much pain as the competition neared and missed out on a spot with the team.
In addition to a nagging back - two bulging discs, a herniated disc and two stress fractures - she was also battling an eating disorder and soon had to make the difficult decision to walk away from the pool. Returning to cheer on her brother wasn't easy at first. She didn't attend the 2000 Games and couldn't even watch on television.
"It's just hard when you see these other people making it, people you were swimming against, and I had no control. I couldn't control my back," she says. "But as I got older, matured more, I looked back on my career and realized I did a lot more than so many others, I should be proud."
In addition to an unmatched work ethic, the Phelps siblings are physically remarkable. Hilary was flexible and limber, and Whitney and Michael are double-jointed.
Michael, in fact, can bend his ankles, wrists and shoulders in just about any direction, allowing him to contort and move in unfathomable ways underwater.
The family has long taken note that the children became progressively elastic - "I always wonder what a fourth child would've been like," Debbie jokes - and increasingly faster.
"It's funny," Hilary says, "because when I was younger, I was gung-ho about practice, swimming was my life and I was a decent college swimmer. Then there's Whitney, who was a little more hesitant to start swimming and then she was really great.
"Michael was different. No way, didn't want to put his face in the water, 'I hate practice, keep me away.' And now he's the best ever."
They cheer him on from the stands day after day, medal after medal, treasuring every moment.
They're here for him. He's here because of them. And they're all here together.