Michael Phelps’ legacy was already set. But the Rio Olympics could be his most gratifying.

Michael Phelps is the most decorated Olympian of all time. He has 18 gold medals, a record. He has 22 overall medals, a record. He won eight golds in a single Olympics, a record. He has 11 golds in individual events, a record. He’s won World Swimmer of the Year seven times, a record. And if he wins gold in Rio, as he’s perfectly capable of, it may be his greatest accomplishment yet.

We were told Phelps was done after his performance in the pool in London, where he won the most medals of any competitor for the third straight Olympiad. Like Alexander the Great, he’d conquered most of the world by the time he was 30, and now it was time to retire. But as Sports Illustrated profiled, the greatest swimmer of all time wasn’t quite ready for life after swimming. In fact, Phelps was kind of a mess. He entered a downward spiral that culminated in a 2014 DUI arrest, his second.

But Phelps went to rehab, swore off alcohol until after the Olympics and got back into elite shape. The suspension from his DUI caused him to miss last year’s World Championships in Russia, but back at home, Phelps posted times good enough to win all three events he would have entered at those championships. Out of the pool, his life has stabilized. He proposed to his longtime girlfriend in 2015; in May they had a little baby boy named Boomer.

So now Phelps finds himself poised to set records not for his prolific career or speed, but his endurance. At 31, downright ancient for a swimmer, he could become the oldest swimmer ever to win an individual gold medal. He’d also be the first swimmer to win individual gold medals 12 years apart. Staying great was easy for Phelps, but going down into the depths and resurfacing may prove his most meaningful achievement.

Unlike past Olympiads, Phelps won’t be participating in a wide slew of events. His body simply can’t handle that anymore. He’s focused on three individual events -- the 100m butterfly, the 200m butterfly and the 200m individual medley. He may also participate in relays.

He has a legitimate shot at winning all three. He had the best time in the world in all three events last year. His 100m fly would’ve out-touched South African Chad Le Clos at the wall, his 200m fly was a half-second better than Hungarian Lazslo Czeh and his 200m IM was about a second faster than the performance that Ryan Lochte won with in Russia.

Can Phelps win all three in Rio? It’s worth noting that his times last year were in a different pool than the World Championship times he beat, which may have been a factor. And this year, Phelps doesn’t have the best time in the world in any of his events. He has the second-best in the 100m fly and the 200m IM, and he isn’t even in the top five in the 200m fly.

But this is Michael Phelps. This really will be his last hurrah and he has three gold medals in his sights. He’s pushed the boundaries of what we’ve thought to be possible over and over again -- what’s one last time?

Phelps’ three medal races will be held Aug. 9 (200m butterfly) Aug. 11 (200m individual medley) and Aug. 12 (100m butterfly).