Patriots tight end Aaron Hernandez underwent shoulder surgery earlier this offseason, but is expected to be ready for the start of training camp in late July, according to a league source.

It is unclear when the injury occurred, and Hernandez is likely to miss both OTA's and the team's minicamp, scheduled to take place in June. He is expected to remain in California to rehabilitate.

NFL Network first reported the surgery.

The 23-year old Hernandez recorded 51 catches in 10 regular -eason games in 2012, missing six contests due to an ankle injury originally suffered in a Week 2 loss to the Arizona Cardinals.

The injury bothered Hernandez throughout the season, his third with the Patriots. Prior to the start of the regular season, Hernandez agreed to a long-term contract extension through the 2018 season.

Hernandez isn't the Patriots only star tight end to undergo surgery this offseason, as Rob Gronkowski had a third procedure on his left forearm following the development of an infection in the area that was originally affected when he broke the forearm on November 18. Gronkowski continues to deal with the infection, and a fourth surgery relating to the injury remains "very likely," sources told ESPNBoston.com.

The Patriots began their voluntary offseason strength and conditioning program on Monday, and the first OTA is scheduled for May 20.