Tabb, a rookie out of North Carolina, was carted from the field with an apparent knee injury during Thursday's practice.
The 6-foot-4, 250-pound Smith, signed on Friday after a workout, began his pro career in 2005 with Tampa Bay. He had his most productive NFL season with the Buccaneers in 2007, catching 32 passes for 385 yards and three touchdowns. Smith also has played for Philadelphia, Cleveland and Cincinnati, spending the past two seasons with the Bengals.
Last season, however, he played in only two games, injuring his biceps in Week 2 and spending the remainder of the year on injured reserve.
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