Most of the attention paid to Patriots tight end Rob Gronkowski this offseason has been in relation to his twice-broken left forearm that has required four surgeries. But a back injury that has hampered him over the last year-plus could affect his availability for the start of the season.
A league source confirmed to the Globe Wednesday afternoon that Gronkowski, 24, will undergo surgery in mid-June to repair a disk in his back.
The injured disk is not the same one that forced Gronkowski to miss the entire 2009 college season at Arizona, but the surgery almost certainly will keep him off the field for the start of training camp in late July.
That means he could start the season on the physically unable to perform list. And it is unclear at this point whether Gronkowski will be ready to play in the season opener Sept. 8 at Buffalo.
If Gronkowski can't play against the Bills, the Patriots will lean on Aaron Hernandez, who is recovering from his own shoulder surgery, plus tight ends Michael Hoomanawanui, Jake Ballard, and Daniel Fells.
As for the forearm, all indications after the fourth surgery (which was done May 20) are that the infection has cleared, and the bone should be healed by the time training camp begins.