Rocker suffered the injury Wednesday night in a scrimmage against Walden Grove, according to Kelly, citing coach Dusty Peace.
Rocker is one of the top prospects in Southern Arizona, having rushed for 1,163 yards and 12 touchdowns in 10 games last season. He also had three receiving touchdowns.
Rocker is listed as a three-star prospect in the 2021 class, according to the 247Sports Composite rankings. He holds listed scholarship offers from Arizona, BYU, Cal and Nevada.
He earned a Tucson Conquistadores/APS Digital Player of the Week award last season after rushing for 213 yards with a touchdown to help defeat Pusch Ridge in Week 4.