Dwyer is one of four restricted free agents the Steelers tendered, and all are expected back. ESPN's Adam Schefter first reported Dwyer's signing.
The Steelers also gave offers to emerging wideout Emmanuel Sanders, a projected starter assuming Mike Wallace leaves; running back Isaac Redman and nose tackle Steve McLendon. Pittsburgh can match any free-agent offers they receive.
Dwyer, 23, ran for 623 yards and two touchdowns last season, averaging 4.0 yards per carry, and could be the featured back with the expected departure of Rashard Mendenhall. He'll have to beat out Redman. Sanders, 25, had 44 catches for 626 yards and a score last season.
For more NFL news, rumors and analysis, follow @EyeOnNFL on Twitter, subscribe to our RSS Feed, watch Pro Football 360 daily at 3 ET and NFL newsletter. You can also follow Larry Hartstein @LarryHartstein.