The New England Patriots have been under fire over the past few weeks regarding former tight end Aaron Hernandez and his charges for murder and as the team heads into training camp, that position and the status of Rob Gronkowski will be something important to monitor.

Gronkowski is going to be the focal point in training camp and according to ESPN.com, the tight end has returned to the Patriots facility to continue recovering from back surgery this offseason. The report says that Gronkowski is doing rehab work at the team facility and is currently focusing on improving his core strength as he tries to get back onto the field.

Sources said that Gronkowski has been recovering well from the surgery, although the team is not sure yet if he will be ready to play against the Buffalo Bills to open the season. Gronkowski went through the surgery last month and that came after having a fourth surgery on his forearm earlier in the offseason after hurting it at the end of last year.

The tight end may start training camp on the physically unable to perform list and Dr. Robert Watkins, who performed the procedure, said the "timing of his return to football will depend on his progression through the rehabilitation program."