Spann is the more well known of the two, having been the practice squad call-up in the Steelers' 2012 season of dreams for back-up running backs. After RB Rashard Mendenhall and Jonathan Dwyer were both placed on the IR, and RB Mewelde Moore nursing a knee injury, Spann joined fellow practice squad mate John Clay on the active roster for the 29-23 (OT) loss at Denver.
Smith was picked up during the off-season, after initially joining the NFL with the Browns in 2009. His release could have been prompted by the seventh-round selection of Texas A&M CB Terrence Frederick, a smart zone corner who is most likely a developmental project at this point. After posting a 4.55 40-yard dash time at the Combine, he ran a 4.42 at his pro day.
Source: Behind the Steel Curtain