ORCHARD PARK, N.Y. -- When naming the NFL's best middle linebackers over the past decade, two stand out: Ray Lewis and Brian Urlacher.

Both were fiery and passionate, the vocal quarterbacks of their respective defenses. Neither was ever at a shortage of words, on or off the field.

Buffalo Bills middle linebacker Kiko Alonso is different.

One of the most quiet and reserved players in his team's locker room, the 46th overall pick in April's draft has let his play speak for itself. Staying on the field for every snap this season, Alonso is the NFL's second-leading tackler and is among the favorites to win the defensive rookie of the year award.

It has been a quick ascent, one that would have seemed unlikely just a few years ago.

Kiko Alonso arrived at the Bills' bye week with 112 tackles and four interceptions through 11 games. AP Photo/Bill Wippert

In February 2010, Alonso was arrested for DUI and suspended for his entire sophomore season at the University of Oregon. That incident preceded a knee injury that would have wiped out his 2010 season, even without his arrest.

Just over a year later, Alonso was arrested again, charged with criminal mischief and trespassing. According to reports, Alonso pounded on the front door of a stranger's home late one Saturday night, demanding to be let in. The owner called 911 and fled. When police arrved, Alonso was inside the house.

He pleaded guilty to the charges and was sentenced to probation, community service and alcohol treatment.

Alonso was suspended again, this time indefinitely, putting his future with the team in peril until Oregon coach Chip Kelly decided to reinstate the linebacker for the 2011 home opener.

Given a second chance, Alonso made the most of it. He tallied 46 tackles as a junior and was named defensive MVP of the Rose Bowl. That led to a senior season in which he notched 81 tackles -- including 14 for loss -- four interceptions and two forced fumbles.

"I take extra pride in that I got the opportunity to coach Kiko," Kelly, now the Philadelphia Eagles' head coach, said this week. "Extremely dedicated, driven person, both academically and athletically."

Alonso played his final college game in Glendale, Ariz., on Jan. 3, a Fiesta Bowl win for Oregon. Four days later, at a news conference more than 2,000 miles away, the Bills introduced Doug Marrone as their next head coach.

The road to Buffalo

The Bills, fresh off their eighth consecutive losing season, had become the NFL's latest rebuilding project. Marrone quickly reeled in New York Jets defensive coordinator Mike Pettine for the same role in Buffalo, and the search began to fill a void in the middle of the Bills' defense.

As the Buffalo winter howled outside, Marrone played the role of scout, reviewing Oregon game film.

"All the sudden, my eyes kept going to the middle linebacker because he made so many plays," Marrone said last week. "Not to say that [Alonso] was the best on it, but it was just someone where you said, 'Wow, this guy is productive on the football field, making play after play, sideline to sideline, downhill.' So now you become interested."

Alonso made a favorable impression on the Bills' contingent at the scouting combine. AP Photo/Dave Martin

The Bills flagged the 6-foot-3, 238-pound Alonso as one player they wanted to interview at February's scouting combine. He quickly impressed Pettine, who had risen through the ranks while coaching some of the NFL's best defenses in Baltimore and New York.

"You could tell that the football aptitude wasn't commensurate with how he presented himself," Pettine said. "He didn't wow you from a communication standpoint, but you could tell that the kid knew football."

"When we put the tape on, [we asked Alonso] 'What were you thinking here?' 'Why did you do this?'" Pettine explained. "[And Alonso said] 'Hey, I did this because I saw the small split by the guard and the tackle was sitting light, and I knew they were going to run overhead.'"

Although Alonso could prove his football knowledge, he still had to answer for his two arrests.

"I just said that I made mistakes," Alonso said last week. "I just moved on. I'm not going to make that mistake again. I'm just smarter, and I know I have to be smarter."

The Bills scouting staff, then led by general manager Buddy Nix, had already developed a profile of Alonso's character, so when the Bills interviewed Alonso in Indianapolis, his off-field missteps warranted only a brief mention.

"I don't know if it was at the beginning or the end [of the interview]. It just was asked in passing," Pettine said. "I think we had already had a detailed report from Oregon. I think everybody felt comfortable with those issues."

"I personally didn't call Chip [Kelly], but I [would] say there was a thorough process," Marrone said. "I don't want to say 'investigate,' because it's almost like you're trying to find bad things about people, but we do a background check. Our scouts talk to the coaches, the weight coaches and people like that."

Two months after interviewing Alonso in Indianapolis, the Bills made him their third pick in what would be Nix's final draft in Buffalo.

The Bills had their guy.

Rookie in the middle

Two weeks later, Pettine flew to Philadelphia for the NFL's Career Development Symposium, an internal networking event at which Kelly was a speaker. The former Oregon coach, then settling into his new position with the Eagles, let Pettine know Alonso wouldn't disappoint.

"He said to me, 'Hey, listen, you guys have the real deal on Kiko now,'" Pettine recalled. "I knew he was high on their draft board. … [Kelly] spoke very, very highly of him. He said that we would be very pleased with [Alonso], and he's obviously been dead on."

The next challenge for Pettine was to gauge how Alonso would fit into his system, a complex scheme that uses multiple defensive fronts and pressures to keep opposing quarterbacks on their toes. Helping Alonso's cause was his background at Oregon.

"You could tell at Oregon that he was really well coached. They did a lot defensively, and they weren't just sort of playing one front and coverage," Pettine explained. "Scout some of these kids, and they just play a four-man front and quarter coverage behind it, and that's it. They've never really been exposed to much, whereas [Alonso] had been exposed to a lot.

"So he was a guy that we felt was ahead of the curve coming out."

Alonso is excelling as a middle linebacker, but his defensive coordinator says the rookie has the ability to play all over the field. George Gojkovich/Getty Images

The Bills needed to find out, however, if inserting a rookie into the center of a complicated defense and having him wear the helmet communication device was another risk they were willing to take.

"In the spring, we were like, 'Hey, let's try it.' That would be the time to do it. And we felt the plan would be, hand it to him, see if he could do it,'" Pettine said. "If he could, he could. Great. If he couldn't, we would have plenty of time to find option two, option three down the road."

It would be the first time Alonso, who communicated with the sideline with hand signals in college, would use the helmet with the radio, a critical role within any NFL defense.

"Very, very important position. He has to get 10 other guys correctly aligned, and then if there's checks that need to be made, he needs to know those checks and make those checks," Bills linebacker Manny Lawson said. "And then, as far as when things do start to break down or things don't go your way, he has to be that guy who everybody looks to."

As it turned out, the transition wasn't difficult for Alonso.

"It's easy," he said. "I mean, [Pettine] just gives me the call in the headset and I echo it. It's actually easier than the hand signals. But they're both easy."

"That was never an issue from day one," Pettine said. "Never an issue."

The final hurdle for Alonso to clear would be winning over his veteran teammates, including Lawson.

"My first impression of Kiko was that he was very soft-spoken, not really understanding his role. Didn't want to step on anybody's toes," Lawson said. "Granted, he was in a position that he was, the center of the defense, the spotlight of the defense, the head guy of the defense. He didn't really know how to take that role, especially coming in as a rookie."

Lawson has already established a level of comfort on the field with Alonso despite the 23-year-old rookie having played in only 11 games for the Bills (4-7) to this point.

"I can take a chance on really extending myself -- diving to go make a tackle -- because I know Kiko is going to be somewhere around if I don't make it," Lawson explained. "Having that extra blanket of security really motivates not only the individual on the field or the other 10 guys that are on the field, but it motivates the entire team."

"Kiko's a special player. When you watch him on film, it's Kiko see ball, Kiko tackle ball," Kelly said. "We saw that at Oregon a lot, and I think people in Buffalo are seeing that right now."

While Alonso has manned the middle of the field for the Bills, Pettine hinted last week that the Bills might eventually decide to tap his versatility.

"To me, you don't even know if [middle linebacker] is his ideal position. It's more of a necessity here with him. But he can play a lot of spots. He's a football player. He could probably play strong safety, defensive end," Pettine said. "He can play. Loves football. That's one of those things where we can move him around and put him in some different positions. He's fine with all of them."

No matter what position he plays, Alonso may never be the Bills' version of Ray Lewis or Brian Urlacher in the locker room or in the pregame huddle.

But on the field, the Bills believe they have something special.

"There's really not a ceiling for him," Marrone said. "Playing every snap, a guy that doesn't come off the field. Obviously, he has the communication that he has to get done. When you look at what's going on and how he's producing, in my opinion -- and, obviously, that's biased -- he's an outstanding football player. Not just as a rookie, but just as anyone at that position."

None of this comes as a shock to Alonso's college coach.

"He made a couple of missteps early in his career and really changed," Kelly said. "I think he understood the opportunities he had in front of him and everything that's happening to him now -- I don't know if it surprises other people. It doesn't surprise me."