Gronkowski, who underwent off-season surgery on his left ankle after suffering a high ankle sprain in the AFC Championship Game against the Ravens, had 90 receptions for 1,327 yards last season.
The total set a record for most receiving yards in a season by a tight end. He set the mark in the last game of the regular season, edging the New Orleans Saints' Jimmy Graham who finished with 1,310. Kellen Winslow had held the previous record with 1,290 yards in 1980.
Gronkowski also had 17 touchdown catches last season, another record for a tight end in a season. Vernon Davis (49ers, 2009) and Antonio Gates (Chargers, 2004) had shared the record at 13.
On Thursday, the Patriots released wide receiver Chad Ochocinco, and signed tight end Bo Scaife.