Rogers-Cromartie a top NFL draft prospect despite having one kidney.

Even the most promising NFL draft prospects come with a downside. And that of Dominique Rodgers-Cromartie is scarier than most.

The cornerback from Tennessee State, among the fastest-rising hopefuls among pro scouts, has only one kidney. He was born with two but one was non-functioning and was removed when he was 8. By all accounts, the situation had no effect on his ability to play.

It could, however, give teams pause when it comes to drafting him. He probably will have to sign a medical waiver to play. That said, Rodgers-Cromartie is widely considered one of the two best cornerback prospects in the class, along with Troy’s Leodis McKelvin, and is expected to be one of the first 20 players selected in the April 26-27 draft.

According to NFLDraftScout.com, Rodgers-Cromartie ran a scoring-fast 4.29-second 40 for scouts and had an exceptional vertical leap of 38½ inches – best among cornerback prospects. The website said that in Rodgers-Cromartie’s 39 college starts, quarterbacks completed only 55 of 161 passes thrown in his immediate area, and that he intercepted 11 of those, deflected 25, and limited the opposition to just 3.54 yards per pass attempt. That’s the best of any collegiate defensive back over the past three seasons.

“He’s a phenomenal athlete who worked out ridiculously well at the combine,” a team scouting executive said. “He had the best ball skills of anyone there. He’s not the most physical guy in the world, but that will come. His potential is off the charts.”

Rodgers-Cromartie wouldn’t be the first to play in the NFL with just one kidney. Former Long Beach State receiver Mark Seay, who lost his kidney as the result of a random shooting, played five seasons for the San Diego Chargers and Philadelphia Eagles.

Even though a defensive back does far more hitting, a receiver is more likely than a cornerback to be in positions in which his kidneys are exposed.

Rodgers-Cromartie is the cousin of San Diego’s Antonio Cromartie, who led the NFL last season with 10 interceptions – not counting his two in the Pro Bowl – and scored an NFL-record-setting touchdown by returning a missed field goal 109 yards.

sam.farmer@latimes.com