HOUSTON (AP) — Kareem Jackson figures starting as a freshman at Alabama prepared him to start for the Houston Texans as a rookie.

Jackson, the 20th overall pick in the NFL draft on Thursday, is expected to replace Dunta Robinson as Houston's starting right cornerback. He was introduced in Houston on Friday.

"I think it will help a whole lot," Jackson said of his early experience at Alabama. "I wouldn't say (starting as a rookie) is pressure. Playing football is something that I love so I'm going to put my all into it. I'm going to come in and I'm going to work hard."

Still, his NFL debut will certainly be much tougher than any game he played in college. The Texans open the season against Peyton Manning and the Colts, a team they've beaten just once in franchise history.

"Someone told me that last night," Jackson said of opening with the Colts. "It's going to be a challenge. I'm looking forward to it. I don't back down from too many challenges. Watching Peyton Manning, he's a great quarterback, but I'll be out there and I'm going to make my presence known."

Jackson had 49 tackles last season while starting each game for Alabama. In a three-year career, he appeared in all 41 games and finished with 159 tackles and 29 pass deflections.

The Texans hope he can upgrade an improving defense filled with young players. Houston ranked fourth in total offense last season and 13th in total defense, with the pass defense ranking 18th.

"We believe that he could be a piece to help us get over some of our humps throughout the National Football League," defensive coordinator Frank Bush said. "We think his presence will make our defense a real physical defense. We need more physical presence on the edge and we think he's going to bring that."

Jackson believes his biggest asset is his physical play, so the Texans look to be getting just what they wanted.

He is the first cornerback taken in the opening round by Houston since Robinson was chosen 10th in 2004. Jackson oozes confidence, saying that he doesn't feel like he has any weaknesses as a player.

"I'm going to improve in every aspect of my game," he said. "I'm going to do the little things, I'm going to pay attention to the little details that are going to help me get better as a player."

The Texans had one pick in the second round and another in the third round Friday night.