Texans OLB Whitney Mercilus (back) out Sunday vs. Jaguars

Houston Texans starting outside linebacker Whitney Mercilus will not play Sunday against the visiting Jacksonville Jaguars due to a back injury, a source told ESPN.

Mercilus saw limited work Wednesday and Thursday, but he was held out of Friday's practice.

Outside linebackerJohn Simon, who has started five games this season, will miss his fourth straight game as he continues to deal with a chest injury.

The Houston Chronicle first reported that Mercilus will not play.