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After recovering from a serious concussion suffered in his rookie season, Colts running back Tyler Varga has decided not to risk another one.

The Colts have placed Varga on the reserve/retired list. His roster spot was filled via the signing of running back Abou Toure.

In May, Varga went public with his experiences from 2015, which resulted in his placement on the retired list after he declined to take medication aimed at helping his recovery due to concerns about potential side effects.

Toure, who like Varga was signed as an undrafted free agent a year ago, spent the offseason and training camp with the Colts, before being released. He later joined the Steelers and Cardinals practice squads.