Merriman listed as questionable

Posted by ESPN.com’s Bill Williamson

San Diego standout linebacker Shawne Merriman is listed as questionable to play Sunday night at Pittsburgh in a pivotal game for the Chargers.

Merriman made significant strides Friday by practicing fully. He has a groin injury and he practiced on a limited basis Thursday after practicing Wednesday. Merriman has missed significant parts of the past two games with the injury.

Meanwhile, San Diego running back LaDainian Tomlinson is listed as probable and he is expected to play at Pittsburgh. Tomlinson has practiced all week. He missed the past two games with an ankle injury.

For Pittsburgh, safety Troy Polamalu was ruled out by the Steelers. It's the third straight game he’ll miss with a knee injury. Expect San Diego to try to exploit Polamalu’s absence by getting the ball to tight end Antonio Gates often.