Merriman was placed on injured reserve Saturday because of a nagging Achilles tendon injury, culminating a tumultuous year for the once-feared pass rusher.
The Bills claimed Merriman off waivers earlier this month, three weeks after he was placed on injured reserve by the San Diego Chargers because of a calf injury.
At the time, he was also nursing a strained Achilles tendon. In his first practice with Buffalo on Nov. 10, he lasted just 15 minutes before re-injuring it.
The 2005 first-round pick and three-time Pro Bowl selection also sat out most of the Chargers' offseason workouts and part of training camp to protest his contract, which expires following this season. He finishes the year with six tackles in three games for the Chargers.
Merriman expressed his eagerness to get a fresh start when he made his first public appearance in Buffalo a day before the Bills' 22-19 loss to Chicago in Toronto in Week 9.
The following Wednesday, he walked onto the practice field for the first time with his new team, but that's when things went awry.
During a harmless-looking individual drill, he backpedaled and then pivoted to his left before pulling up and hopping on one leg.
He immediately pulled down his right sock and limped to the sideline, where a trainer spent a few minutes checking his ankle. Merriman then consulted head trainer Bud Carpenter at midfield before being escorted to the Bills' fieldhouse, where the team's training room is located.
Merriman was inactive for the Bills' next two games against Detroit and Cincinnati. On Friday, coach Chan Gailey declared Merriman out for Sunday's home game against Pittsburgh, 24 hours before the team officially cut short his season.
Nicknamed "Lights Out" for his aggressive and hard-hitting style, Merriman has 43½ sacks in his 60-game career. But his production has dropped substantially the past three seasons, largely due to nagging injuries, including reconstructive knee surgery that forced him to miss most of the 2008 season.
Since the start of the '08 campaign, Merriman has just four sacks in 18 games.
Merriman was suspended four games in 2006 after testing positive for steroids. He blamed the positive test on a tainted supplement, which he never identified.
He also brought unwanted attention off the field after being arrested just before the 2009 season when reality television star Tila Tequila accused him of battery and false imprisonment at his suburban San Diego home. No charges were filed, and Merriman and Tequila settled dueling lawsuits.