Paris a reality check for Dressel

Caeleb Dressel (right) knows the age-group days of "simply swimming" can never return for a seven-time Olympic gold medallist.

But despite devastating lows that drove him away from the sport for the better part of a year and admitted uncertainty over whether he'll ever return to his best, the 27-year-old American once touted as the heir to Michael Phelps, is ready to test himself again at the Paris Olympics.