The 29-year-old superstar is qualified for the world meet in the 100-meter freestyle, 100 butterfly and 200 individual medley. He could swim in up to three relays, for which lineups are decided by the coaching staff.

After it was announced that Phelps wouldn't swim in Russia, Olympian Ryan Lochte was named to replace him in the 100 free, Olympian Tyler Clary took his place in the 200 IM and Tim Phillips was added to the team for the 100 fly.

Phelps came out of retirement last year with his sights set on competing at a fifth Olympics in Rio. Not competing at the world meet would prevent him from measuring himself against the best swimmers, but wouldn't affect his chances of competing in the Olympics. The US team for Rio will be chosen at trials next summer.

Phelps' arrest came about a month after he won three golds and two silvers at the Pan Pacific Championships on Australia's Gold Coast. He retired after the 2012 London Olympics, having won a record 18 gold medals and 22 medals in four games.

He has since attended a rehab program and got engaged recently.

Conversations about Phelps' possibly swimming at worlds were first reported by ESPN.