PITTSBURGH — The Steelers‘ $20 million tight end experiment has come to an end after one season.

The team released Ladarius Green with a failed physical designation Thursday. Green signed a four-year free-agency deal that paid him $6.25 million last season, but he was limited to six games because of an ankle injury, which required surgery, and a concussion.

Green also had concussion concerns while playing for the Chargers.

Green produced 18 catches for 304 yards and a touchdown in those six games. Because of his 6-foot-6 frame and speed, he was considered an ideal fit for the Steelers’ vertical passing game.

But he couldn’t stay on the field. The concussion cost Green a playoff run.

The move saves the Steelers $2.625 million in salary cap space this season, according to Overthecap.com.

Jesse James will enter next week’s organized team activities as the lead tight end.

A fifth-round pick in 2015, James was a reliable pass-catcher in the playoffs, totaling 10 catches for 131 yards against the Kansas City Chiefs and New England Patriots.

The Steelers also like the potential of young tight end Xavier Grimble, and they still have David Johnson as a blocking tight end.

Overall, though, the Steelers have struggled to replace tight end Heath Miller, who retired before the 2016 season. Miller ranks third in franchise history with 592 receptions in 11 seasons.

Green had hoped to help with that process, telling ESPN in March that he was excited to take part in offseason workouts and bounce back from injury in 2017.

The Steelers looked hard at selecting a tight end in last month’s NFL draft but got help at receiver instead, taking USC’s JuJu Smith-Schuster in the second round.