Posluszny quickly made his presence known on the football field and quickly became a fan favorite in Buffalo.
In his first NFL game, Poz recorded 10 tackles, nine of them solo. A Week 3 injury cut short the rest of his rookie campaign, but his 26 tackles after three weeks were third in the NFL.
The 2008 season was his only full season in Buffalo, and his No. 51 jersey was a very common sight at Ralph Wilson Stadium. He finished the season with 110 tackles, one forced fumble and one interception, earning him the 2008 Bills Defensive Player of the Year.
Due to his 2008 efforts, Posluszny was named the defensive captain for the Bills heading into the 2009 season. Injuries again cut short his season, and he finished with 111 tackles, one sack, three forced fumbles and three interceptions in 12 games played.
The 2010 season would be Posluszny's last in Buffalo, and his best. In 14 games, he recorded 151 tackles and two sacks.
Heading into the 2011 season, Poz was a free agent and publicly said that he wished to remain a Bill. However, Posluszny followed the money and bolted to Jacksonville, inking a six-year, $45 million contract.
This left a major void in the Buffalo defense.
Poz was a fan favorite, and the middle linebacker was the face of the Bills' defense. He was a tackling machine who claimed he wanted to be a Bill, but he did what a number of high-profile Buffalo free agents have done: bolted.
Buffalo got a gift when Green Bay cut ties with Nick Barnett, and he replaced the void in the Bills' defense.
Here are the stats for Posluszny and Barnett since leaving and coming to Buffalo, respectively. (Stats as of Week 12 of the 2012 NFL season.
Barnett is now an outside linebacker in Buffalo's new 4-3 defense, but he has done a great job of replacing Poz.
The beauty of it all is that Barnett signed a three-year, $12 million deal.
Poz was a crowd-pleaser and a sure tackler, but Barnett is the bargain and has playoff experience.
His presence has certainly been comparable to Poz's, and for his price, Bills fans might be more pleased with Barnett.