The Facts: The 49ers addressed their injury-riddled running back corps Monday by agreeing to terms with Smith, according to a league source.

Diehards Line: Smith joins a unit hit hard by injuries since training camp practices began Thursday. Kendall Hunter, the incumbent No. 2 back behind Frank Gore, sustained a season-ending knee injury Friday, then LaMichael James dislocated an elbow Sunday that could sideline him for a month. Marcus Lattimore still isn't ready to return to full work after a season off. ... Smith (6-foot-1, 208 pounds) spent the past four seasons with the Cardinals, establishing himself as a pass-protecting back on third downs and as a core special-teams player. None of which is likely to keep rookie Carlos Hyde from getting a much greater opportunity to work behind Gore this summer.