After years of controversy and hard partying, Michael Phelps s teammates recognize his new-found maturity and elect him captain

It’s been lonely at the top for Michael Phelps. At least, until now, as he’s been elected along with five of his veteran teammates to captain the U.S. swim team for the Rio Olympics.

Despite competing in his fifth Olympics next month, and already the most decorated Olympian in history, Phelps, 31, has never been named captain. It was hard to imagine him as a role model after years of hard partying that led to a second drunk-driving arrest in 2014.

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But Phelps has made a remarkable personal U-turn since entering rehab for substance abuse in 2014.

And in a nod to his rebound, on Monday night at their training camp in San Antonio, Texas, the 47 members of the US Olympic Swimming Team voted Phelps co-captain of the men’s team, along with sprinters Nathan Adrian, 27, and Anthony Ervin, 35. Leading the women’s team will be butterfly ace Cammile Adams, 24, backstroker Elizabeth Beisel, 23, and Phelps’ pal and housemate, six-time Olympic medalist Allison Schmitt, 26. All six are first-time captains and have qualified for a jaw-dropping 19 Olympics appearances combined.

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“It’s a fantastic group, with the next generation of swimmers being led by some very experienced veterans,” coach Mike Bottom says.

Phelps’ sister Hilary says that his therapy in rehab may have made Phelps more approachable to teammates. “There was always a little bit of a bubble around him, that was there for a long time,” Hilary Phelps tells PEOPLE. “There was a feeling that people wanted to give him space. Now that he’s more grounded, he’s warmed up and people have warmed up to him. He s let people know, ‘I’ve made mistakes, like everyone else. I’m human.’ And people respond to that.”

Phelps is the all-time Olympic leader, with 22 medals. He has earned 18 gold medals, twice as many as the second-highest gold winners. He claimed the 2012 Olympics would be his last, and then, under criticism for a lackluster performance in London and public displays of substance abuse, reversed himself. USA Swimming suspended Phelps and forced him to withdraw from the 2015 world championships after he was arrested for drunk driving in Baltimore in September 2014. He sought treatment in Arizona less than a week after his arrest.

“I think (in rehab) Michael learned that he had a good person inside of him, and that he was more than just a swimmer,” Hilary says. “He is so much more invested in life.”

It helps, she adds, that he became a father in May, when his fiancee Nicole Johnson gave birth to their son, Boomer.

“Michael s story of sobriety and having a child has been great,” says USA Swimming coach David Marsh. “It s the right time for him to show leadership.”