FOXBORO (AP) -- New England Patriots tight end Rob Gronkowski has undergone back surgery.
The operation was performed on Tuesday by Dr. Robert Watkins and was successful, said Drew Rosenhaus, Gronkowski's agent.
On May 20, Gronkowski had his fourth surgery on the left forearm that he broke on Nov. 18 while blocking for an extra point in a 59-24 win over the Indianapolis Colts. He broke it again in the Patriots' first playoff game, a 41-28 win over the Houston Texans. Rosenhaus said the fourth surgery was expected to be the last on his forearm.
The Patriots open training camp in late July and start the regular season on Sept. 8 at Buffalo. In 43 NFL games, Gronkowski has scored 39 touchdowns, 38 on passes and one on a run.