Kevin Duffy of the Boston Herald first reported the move.
Hill impressed in three preseason games, taking 26 carries for 107 yards (4.1 yards per attempt) and a touchdown, particularly showing out in the first two tilts. Gillislee finished with 33 carries for 100 yards (3.0 yards per carry) in three preseason games.
Gillislee signed a front-loaded, two-year $6.4 million contract last season, but was a healthy scratch down the stretch. Jettisoning the 27-year-old saves the Patriots $2.18 million on the salary cap.
Despite losing his roster spot in New England, Gillislee showed last season he's still solid in converting short-yardage situations. He should land on his feet elsewhere (finding his way back to Buffalo to spell LeSean McCoy might not be a bad deal for Gillislee).