Underwood, a seventh-round pick out of Rutgers in 2009, has played with Jacksonville, New England, and Tampa Bay.
In his last two seasons with the Buccaneers, Underwood has 52 catches, 865 yards and 6 touchdowns.
Carolina continues to bring in an array of players at the wide receiver position after gutting Cam Newton‘s options earlier this offseason. Underwood could find himself at the top of the depth chart with the newly signed WR Jerricho Cotchery, for the time being.
Pro Football Focus rated Underwood No. 87 out of 111 wide receivers in 2013.