Stephfon Green, running back for the Penn State Nittany Lions, has signed as an undrafted free agent with the Detroit Lions on Monday, according to Ron Musselman of StateCollege.com.

After some earlier confusion, free-agent RB Stephfon Green has signed with the Detroit Lions, joining OL Quinn Barham.

— Ron Musselman (@rmusselmansc) April 30, 2012

In a Penn State career marred with disciplinary problems, Green ran for 14 touchdowns and one receiving touchdown in four seasons. Last season, he ran for 266 yards on 61 carries. He joins fellow Nittany Lion Quinn Barham, who also signed with the Lions. Barham started at tackle in 2010 at Penn State and did so again in 2011.

Here's more on Penn State undrafted free agents.

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