Financial details of the four-year contract were not yet available. Ryans is the second of Houston's seven selections in the 2006 draft to come to contract terms. In a slack signing period, Ryans is also the third player leaguewide from the second round to complete a contract.
"I think he's a heck of a football player," Texans general manager Rick Smith said on Friday night. "We're excited that he's in the fold and excited to watch him grow and mature as a football player. He's got all the intangibles to be a solid NFL player."
Most franchises tend to work from the bottom up on their early draft choice signings, but the Texans began at the top, signing first overall choice Mario Williams to a six-year, $54 million contract two days before the draft and now have followed up with Ryans, the opening pick in the second round.
ESPN.com has learned the Texans are also very close to a deal with offensive tackle Charles Spencer, the first of the club's two selections in the third round, and that a deal could be reached early next week. A guard for much of his career at the University of Pittsburgh, Spencer will compete for the starting job at left tackle.
With the Texans switching to a conventional 4-3 defense after having played a 3-4 alignment for each of their first four seasons in the league, Ryans will have an opportunity to contribute quickly. The former Crimson Tide standout started at all three linebacker spots during his college tenure but is projected by Houston as a weakside player. He will challenge veteran Morlon Greenwood for the top spot on the depth chart at that position.
While there has been a lull in signings around the league, with management officials from most teams on vacation, the Texans have quietly been hard at work in negotiations. Ryans acknowledged Friday night that he was relieved to have the business end of things settled well in advance of training camp.
"When you play in college," he said, "you don't have these issues. You just go out and have fun. Now [in the NFL], you have to handle the business side of it, too. We have that side of things done now."
Ryans has solid size (6-foot-1, 236 pounds) for the position and is a very active and athletic defender. At the combine workouts, he posted a 4.65-second time in the 40 and had a 39-inch vertical jump and a long jump of 10 feet, 9 inches.
For his college career, he totaled 308 tackles, fourth-most in school history, and led the Alabama defense in tackles each of his final three seasons.
Len Pasquarelli is a senior NFL writer for ESPN.com.