What was feared is now decided.

Chargers linebacker Dwight Freeney is out for the year.

The 12th-year veteran will require season-ending surgery to repair a torn quad tendon a source said Tuesday. He was placed on injured reserve the team signing outside linebacker Thomas Keiser from the practice squad in a corresponding move.

Freeney tore his quad late in the second quarter Sunday against the Cowboys when rushing quarterback Tony Romo. Left tackle Tyron Smith appeared to grab Freeney's shoulder pads from behind to slow his momentum.

A flag thrown for holding was waved off after discussion between the officiating crew.

The loss is a significant blow to the Chargers pass rush. Freeney was an invaluable part of it leading the team with 15 quarterback hurries and three hits.

The responsibility of replacing his production doesn't fall alone on one man's shoulders. Larry English however will be part of the collective effort to better pressure the quarterback starting in Freeney's place for the foreseeable future opposite Jarret Johnson.

Rookie sixth-round pick Tourek Williams is part of the rotational depth.

Keiser joins him. From 2011 to 2012 the 24-year-old had 17 tackles 4.5 sacks and one interception in 12 games with the Panthers. He is among the young players on the roster who have closely watched Freeney on the job asking questions to strengthen their own game through his.

Options in free agency are considered bare.

Freeney 33 signed a two-year $8.75 deal in May.