Patriots tight end Rob Gronkowski will have a fourth surgery on his left forearm in the coming days, to determine if the infection that has plagued it over the past couple of months is finally gone and if that is the case, to again replace the plate that has been placed over his ulna.
But there might still be another problem to address: a league source said Gronkowski has been having back issues dating back to last season.
The USA Today reported that the problem is with a disc, and the issue may be enough of a concern to require surgery. Gronkowski recently had an MRI to check on the injury.
The Patriots announced that second-round pick Jamie Collins has signed his contract. Full story for BostonGlobe.com subscribers.