Brett Keisel injury: Steelers lose defensive end at end of third quarter

In a game in which the defense has held on, but hasn't yet broken, the Steelers lost defensive end Brett Keisel when he limped off the field at the end of the third quarter.

Ziggy Hood replaced him, the second game into his benching.

Steelers coach Mike Tomlin challenged the spot of the ball after wide receiver Marlon Brown stepped out of bounds before the 19-yard line. Perhaps he wanted to buy some time to get Keisel back on the field.

He didn't come back anyway, and the Steelers held the Ravens on a third and short situation. They got it on a sneak by quarterback Joe Flacco.

Keisel's loss will be felt if this game continues as close as it's been. The lack of big play production has cost this team throughout this season - and the last two, for that matter - and the defense is heading down that path again in this game.

Justin Tucker hit his third field goal of the game, bringing the score to 13-9 in the fourth quarter.

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