HOUSTON -- Following the Buffalo Bills' AFC wild-card playoff loss to the Houston Texans, linebacker Lorenzo Alexander's demeanor differed from that of his teammates.

Not to say he wasn't disappointed by the loss, but he seemed at peace; with both the finality of the Bills' 2019 season and of his NFL career.

The 15-year veteran announced his retirement after the game, doing so on his terms. He played all 16 games in each of the final six seasons; he was a two-time Pro Bowler and a second-team All-Pro in 2016, his first season in Buffalo. With little left to prove, Alexander said it was time to start thinking of those who supported his career off the field.

"Oh, I'm done. I made the decision a while ago, so I'm at peace with it," he said. "It's more about choosing my family than not choosing football. I've played 15 years, no regrets at all. ... It's been a great ride, I've loved every minute of it."

The University of California product entered the NFL in 2005 as an undrafted free agent -- at defensive tackle. In a career that deserves its own case study, Alexander split time on various practice squads as a defensive tackle, offensive lineman and tight end from 2005 through 2007, before converting to outside linebacker with Washington in 2010.

His position change proved to be career-altering; he made the Pro Bowl as a special teamer in 2012 but truly broke out during his first season in Buffalo in 2016. Playing on a one-year deal, Alexander recorded a career-high 12.5 sacks.

His presence in the locker room and the effect he had on a rebuilding franchise made him a mainstay when coach Sean McDermott and general manager Brandon Beane arrived in Buffalo in 2017.

"To see him develop into a man and what he became -- you talk about reinventing yourself," said Beane, who worked with the Panthers when the team signed Alexander to the practice squad in 2005. "I don't know anybody who's played in the league who started as a D-tackle and finished as a linebacker. Off the field, what he did and what his family brought to this community [is] second to none. He'll be missed."

Alexander spoke calmly and confidently about his decision to retire following the loss to the Texans, saying he wouldn't let an emotional game like the loss in Houston factor into a decision he had already made with his family.

He enjoyed a longer-than-average career but insists his most prominent role now needs to be that of a father to children Mason, Vanessa, Miles and Zoie, and a husband to wife, Manjanique.

"She's played such a vital role in my success," he said. "It's time for me to allow her to do some of the things that she wants to do and just be a supportive husband and stay-at-home dad."

Alexander ends his career as one of the NFL's most versatile players -- part of the reason he branded himself a "OneManGang" on social media.

More so, he is a Walter Payton Man of the Year finalist, a community staple and, as he put it, "a Bill for life."

He leaves the organization in a better place than when he arrived and said he is proud of the role he played in helping shift the culture within the Bills' franchise. Alexander even helped recruit free agents during a pivotal 2018 offseason -- including return specialist Andre Roberts.

"It's been great to be a part of something special," Alexander said. "I think we've started to set this organization on the track to where it can be a perennial playoff team. ... There's a lot of great young men and women in that building and hopefully, I impacted their lives in a positive way."

He's not ready to leave the team quite yet; Alexander said he would like to remain with the Bills in some capacity -- possibly as a TV or radio analyst.

But leaving the game on the field? An easy decision.

"All the reasons why I would come back would be selfish reasons," he said. "It would be all about me and not about [my family], because I've accomplished everything outside of winning a Super Bowl. ... I'd rather choose my family."