The San Diego Chargers announced that they have placed linebacker Shawne Merriman on injured reserve.

Merriman, who has been bothered by knee injuries the last two seasons, injured his calf during the team's Week 3 loss to the Seattle Seahawks and was not active the following week against the Arizona Cardinals. Merriman played a reserve role in Sunday's loss to the Oakland Raiders, registering a pair of tackles, upping his season total to six, none of which are quarterback sacks.

A first-round pick out of Maryland in 2005, Merriman has 231 tackles and 43.5 quarterback sacks during his career. Merriman was named the NFL's Defensive Rookie of the Year in 2005, and earned Pro Bowl and All-Pro honors after each of the first three seasons in the league.

A knee injury limited Merriman to just 15 games and 4 quarterback sacks between 2008 and 2009, which in addition to a high-profile legal entanglement with a former reality-television star ex-girlfriend, hindered Merriman's attempts to receive a long-term contract extension.

Merriman changed agents this off-season, replacing Tom Condon with David Dunn, who became Merriman's third agent in five seasons.

Due to the uncapped season, Merriman was not eligible for unrestricted free agency, and was tendered at the "First- and Third-Round" level, which carries a $3.269 million base salary.

The Chargers used a "minor injury designation", which requires the team to release Merriman with an injury settlement once he's healthy.

Free agent linebacker Antwan Barnes has been signed to replace Merriman on the 53-man roster.