Patriots tight end Rob Gronkowski underwent back surgery with noted specialist Robert Watkins in California on Tuesday, and ESPN's NFL Insider Adam Schefter reports that the procedure is believed to have gone "well."
The exact recovery time for Gronkowski's back is unknown, but it has been estimated to be in the range of 12 weeks. The Patriots have not yet announced the opening date of training camp, but it is not expected that Gronkowski will be available when it starts sometime in late July.
Gronkowski's surgery comes on the heels of a fourth surgery on his left forearm, which was initially broken in November. Fellow tight end Aaron Hernandez is also coming off of surgery this offseason, and the Patriots currently have an NFL-high seven tight ends on the roster.