Merriman, who earned the nickname "Lights Out" when he was one of the NFL's most feared players, was placed on season-ending injured reserve on Tuesday because of a right Achilles' tendon injury. It's the same injury that forced the Bills to place him on IR last November after they signed him as a free agent following his release from the San Diego Chargers.
"Shawne has worked extremely hard, but unfortunately his Achilles flared back up and it doesn't appear that he will be able to return to the field anytime soon," Bills general manager Buddy Nix said in a statement released by the team Tuesday. "We felt it was in the best interest of our team and for Shawne to put him on IR."
After being bothered by a nagging shoulder injury for the past month, Merriman's Achilles suddenly became a problem on the Thursday before the Bills' 27-24 loss to the New York Giants. Merriman missed that game, but he expressed confidence that he'd be able to return and not miss any significant time when the Bills came back from the bye.
In a statement released by his publicist, Merriman said the Achilles has become so aggravated it is in danger of rupturing.
"I have been advised that it would be in my best interest to undergo surgery as soon as possible in order to prevent a major injury," Merriman said. "I would like to thank all of my fans for their continued support on my road to a full recovery and am looking forward to getting back out on the field."
Merriman's injury leaves a severe dent in a Buffalo pass rush that's generated only four sacks this season. Coach Chan Gailey and several players spoke last week about the need to pressure the quarterback to take the heat off Buffalo's defensive backfield, which has allowed 300-plus yards passing three times already this season.
Overall, Buffalo ranks 31st in total defense.
"I think we just need to keep fine-tuning the things that we're not doing well," Gailey said. "I think what we're doing is good, but I think we're not doing it very well. We're playing hard, we're not playing better."
Merriman's season was average at best, mostly due to his inability to stay healthy. After recording a pair of sacks in Buffalo's preseason opener against Chicago, he hurt his right knee in practice. That kept him out of two preseason games.
He then hurt his shoulder in Week 2 against Oakland, and the Bills began to monitor both his playing and practice time. That basically made him a part-time player.
Nix has always been a big believer in Merriman after previously working in the Chargers front office when they made Merriman their first pick (12th overall) in the 2005 draft. Hoping Merriman could rekindle some of his past glory with a Bills defense that was in desperate need of a pass-rushing specialist, Nix re-signed Merriman to a two-year deal just a day before Buffalo's 2010 season finale at the New York Jets.
A three-time Pro Bowl selection, Merriman finishes the season with nine tackles, one sack and five games. Coming into the season, he had 43½ sacks in 60 career games -- but only four sacks from 2008-10 when his production was slowed by injuries.
He missed most of the 2008 season after undergoing reconstructive knee surgery, and after sitting out most of the 2010 offseason workouts and part of training camp to protest his contract status, he was slowed by an Achilles' tendon injury and then a calf injury before being released.
Information from The Associated Press contributed to this report.