Velez competed for the Puerto Rican squad in the men's 100 m breaststroke at the 2008 Summer Olympics in Beijing. Five months before the Games, he threw down a lifetime best of 1:03.63 to slip past the FINA B-cut (1:03.72) by almost a tenth of a second (0.1) at the All-American Championships in Austin, Texas, United States. Velez slipped to the front from lane one to touch the wall first in heat three with a remarkable Puerto Rican record in 1:01.80, slashing 1.83 seconds off his own entry standard and beating India's Sandeep Sejwal, who finished behind him, in a close finish by only a small fraction of a second. Despite his outstanding feat in the heats, Velez ended his Olympic campaign with a thirty-third place overall finish and did not advance to the semifinals.