Texas A&M cornerback Brandon Williams (21) takes on Arizona State wide receiver Devin Lucian last season.

Brandon Williams doesn't have cable, so he was hanging out in the locker room at Texas A&M Friday night so he could watch the NFL draft.

Truth be told, though, he wasn't expected to hear his name. Not yet, not after the running back-turned-cornerback just made his position switch this past season. He admitted he wasn't even sure if he was going to be drafted at all.

"It don't even feel real right now, to be honest," Williams said.

But, Williams added, "I always knew I'd be in the NFL. I never doubted myself. … I knew some way, somehow, if

someone gave me a chance, I would take advantage of it."

The Cardinals, who needed to add a cornerback, became that team. General Manager Steve Keim had only one pick on the second day of the draft – the second-round choice went to the Patriots last month in the trade for Pro Bowl pass rusher Chandler Jones – making for a long wait until the end of the third round.

"The good thing was we had some healthy snacks up there (in the draft room)," Keim quipped.

By the time the pick arrived, Williams, at 5-11 and able to play press man coverage and having run a 4.37 40-yard dash at the Scouting combine, was someone the Cardinals wanted.

Despite his position change, Williams was a team captain, something that always grabs Keim's attention. His body type and upside as a cover corner "fits our scheme perfectly," coach Bruce Arians said. There will be a learning curve but "we play a lot of 'cat' coverage – you got that cat," Arians said.

"It is amazing the guy played running back the majority of his career and he is able to transition that quickly and play in the SEC against some of the top competition and have success," Keim said.

Arians said the Cardinals could still sign a veteran cornerback, but "I don't see us needing one."

Williams also excels on special teams, an area Keim said the Cardinals have been neglecting a bit recently with the

signing of so many one-year veterans who do not add to that part of the game. Arians said Williams will make an immediate impact.

A highly-recruited running back, Williams started his college career at Oklahoma, where he was a teammate of Cardinals safety Tony Jefferson and playing as a freshman in 2012. He transferred after just one season to A&M to be closer to his daughter.

Last season, new A&M defensive coordinator John Chavis, who came from LSU, was the one who wanted Williams to move to defense. Williams, who faced a running back-by-committee situation, saw a chance to start on defense and just wanted the ability to play as much as possible to help the team.

It was not an easy year. Williams had never played defense, not even in high school. He gave himself a grade of "C" in his first year at cornerback. He had 37 tackles and seven pass deflections.

"I'm very honest with myself," Williams said. "I think I did OK. I could've done way better."

But Williams insisted his learning curve "will be shorter than what people think." It is a risk, Keim acknowledged, but he reiterated there are risks with every pick. Williams sounded predictably confident he will be able to make a career in the NFL as a defensive back.

Then it was pointed out to Williams that cornerbacks last longer than running backs in the NFL.

"They do, huh," Williams said.

And then he let out a big laugh.