He was drafted with the 38th overall pick by the Nashville Predators in the 2008 NHL Entry Draft. On May 28, 2010, the Predators signed Josi to a three-year entry-level contract. On November 26, 2011, Josi made his NHL debut in a 4-1 loss against the Detroit Red Wings. On December 10, 2011, he scored his first NHL goal against Dan Ellis of the Anaheim Ducks.