Shaw, whom Steve Spurrier has praised as the best quarterback in school history, took over for good early in the 2011 season and finished with a 27-5 mark as a starter.
Onetime walk-on Perry Orth and freshman Lorenzo Nunez also started a year ago, managing a turbulent season in which Spurrier resigned midseason and the Gamecocks finished 3-9.
The Gamecocks start the year with two SEC road games, at Vanderbilt and at Mississippi State, so Muschamp does not want an unsettled situation behind center.
Orth, a fifth-year senior, once worked in a Publix grocery store to pay for college before getting a scholarship last season.
Orth's best showing came in the season's final game, when he threw three touchdown passes in a closer-than-expected 37-32 loss to No. 1 Clemson.
Bentley, whose brother Chas Dodd was Rutgers' starting quarterback, had an offer from Alabama but chose to follow his father, Gamecocks running back coach Bobby Bentley, to South Carolina.
