Prater, 25, was a fifth-round pick by the Bengals in 2012, but landed on the injured-reserve with a knee injury and was waived the following offseason. He later caught on with the Eagles before joining the Vikings for the past two seasons.
In 2014, he appeared in 10 games and accumulated two tackles on special teams.
Patterson, 22, was an undrafted free agent out of Ball State and has played in two games for the Colts this season. He has tallied two tackles at this point in time.