Smith originally hurt his groin in the Ravens' Week 6 victory over the Dallas Cowboys, but he did not miss any playing time prior to last week. Smith experienced tightness during pregame warm-ups before a game against the Raiders, and he did not enter the game.
Baltimore already lost corner Lardarius Webb to a torn ACL, so the Ravens can ill-afford a season-ending injury to the second-year player out of Colorado. Smith's status for Sunday's game against the Pittsburgh Steelers was already in question before the surgery, so it appears likely he will be inactive against Pittsburgh.
To bolster the team's depth in the secondary, Baltimore signed veteran cornerback Chris Johnson. Johnson has played nine years in the NFL and spent the last four seasons with the Raiders. The veteran only played four games last season before Oakland released him in March. Johnson did not play with any team during training camp, but the Ravens signed him on Tuesday after a workout earlier in the day.