Matthew Grevers (L) of USA poses with his gold medal after winning the Men's 100m backstroke at the FINA World Short Course Swimming Championships at the Sinan Erdem Dome on December 13, 2012 in Istanbul. AFP PHOTO/MIRA
Matt Grevers of USA competes in the Men's 50m Backstroke heats on day three of the 12th FINA World Swimming Championships (25m) at the Hamad Aquatic Centre on December 5, 2014 in Doha, Qatar.
Credit: Clive Rose
Matthew Grevers swims in the Men's 100 Backstroke during day two of the 2012 AT&T Winter National Championships on November 30, 2012 at the Lee and Joe Jamail Texas Swimming Center in Austin, Texas.
Credit: Ronald Martinez
Matthew Grevers, Brendan Hansen, and Michael Phelps of the United States cheer on team mate Nathan Adrian as he finishes the Men's 4x100m Medley Relay on Day 8 of the London 2012 Olympic Games at the Aquatics Centre on August 4, 2012 in London, England.
Credit: Chris McGrath
Matt Grevers celebrates after he won the championship final of the Men's 100 m Backstroke during Day Three of the 2012 U.S. Olympic Swimming Team Trials at CenturyLink Center on June 27, 2012 in Omaha, Nebraska.
Credit: Jamie Squire
Ryan Lochte, Scot Robinson and Matt Grevers compete in the second semifinal heat of the Men's 100 m Freestyle during Day Four of the 2012 U.S. Olympic Swimming Team Trials at CenturyLink Center on June 28, 2012 in Omaha, Nebraska.
Credit: Al Bello
Matt Grevers competes in preliminary heat 9 of the Men's 200 m Backstroke during Day Five of the 2012 U.S. Olympic Swimming Team Trials at CenturyLink Center on June 29, 2012 in Omaha, Nebraska.