Detroit drafted the former Illinois standout in the second round last year and he missed his rookie season because he tore his left Achilles tendon in training camp.
The rookie was injured after being hit high by defensive end Cliff Avril during practice Monday.
Leshoure said Tuesday that he will skip his senior year. He set Illinois’ single-season rushing record last fall with 1,697 yards.
Leshoure ran for 184 yards and a career-high three touchdowns and set five school records as Illinois earned its first bowl victory since 1999, beating Baylor 38-14.