Phelps, 31, still the big fish who will hook most viewers
GREATNESS can be hard to define but two words suffice for Olympic swimming - Michael Phelps.
Despite a global cast of world-record holders, champions and swim sensations preparing to light up the Rio pool, the greatest of all time will again be the centre of attention at his farewell Games.
Phelps, who retired in 2012 before a rethink, may not win the most medals but his fifth Olympics are about more than that.
"I wanted to do this for me," he said at the United States trials.
The 31-year-old has three individual events (100m butterfly, 200m butterfly and 200m individual medley) plus relays with a younger-looking US team who have rung some changes since London.
However big the splash he makes, Phelps is ratings gold as he seeks to add to his record haul of 18 Olympic titles and 22 medals.
Winner of the 100m butterfly and 200IM at the past three Olympics, he can become the first swimmer to win the same individual event at four Games in a row.
He is not the oldest US swimmer in Rio, however, with former bad boy and 2000 gold medallist Anthony Ervin back at 35.