Steelers round out QB depth chart with Zach Mettenberger

PITTSBURGH -- By claiming quarterback Zach Mettenberger off waivers, the Pittsburgh Steelers have solidified their quarterback room for the 2016 season.

This appears to spell the end for veteran Bruce Gradkowski, who is headed to Reserve Injured with a significant hamstring tear, according to a source. Gradkowski suffered major injuries in back-to-back years, so the team turns to an intriguing prospect who started NFL games less than two years ago.

Gradkowski last threw an NFL pass in 2012 with the Cincinnati Bengals.

I'm told Landry Jones is expected to retain the No. 2 job. For all the flak Jones gets for past uneven play, he's still better than some primary backups around the league. He was slinging it Friday against the New Orleans Saints, completing 19-of-22 passes for 206 yards and a touchdown.

It's hard to know what to expect from Mettenberger after the Titans and Chargers both moved on from him, but the Steelers likely see him as a developmental player who could mold into a No. 2 one day.

The Steelers have shown a commitment to carrying three quarterbacks on the 53-man roster. They played three of them last season. They hope they don't have to this year. But Mettenberger is about the best third option the team will find this close to the season.