A season that started with great promise came to a premature end Tuesday for Miami Dolphins running back Knowshon Moreno.

Moreno was placed on season-ending injured reserve with a torn anterior cruciate knee ligament.

To replace Moreno on the roster, the Dolphins (2-3) reinstated defensive end Derrick Shelby.

Shelby was suspended Oct. 5, one day after his arrest on charges of trespassing and resisting arrest stemming from a nightclub incident.

“I want to apologize to Stephen Ross, Coach Philbin, my teammates and our fans,” Shelby said in a team-issued statement. “I accept responsibility for the distraction I caused the team last week. I have learned from my past actions and am fully committed to representing the Dolphins organization in a first-class manner on and off the field.”

Coach Joe Philbin said in a team statement that Shelby understands the terms of his reinstatement.

“We have completed our process and have made the determination to reinstate Derrick. Derrick understood that he would be held accountable for his actions as they did not represent our organizational standards,” Philbin said.

Moreno also suffered a torn ACL in 2011 as a member of the Denver Broncos.

He signed a one-year, $3 million deal in free agency after a career year in Denver’s top-ranked offense in 2013.

Moreno rushed for 134 yards on 24 carries in his debut with the Dolphins on Sept. 7, but was lost for two weeks with a dislocated elbow at Buffalo in Week 2. He had one carry for four yards in the loss to the Bills.

In his first game back Sunday, Moreno carried six times for 10 yards.

The injury puts the featured back tag squarely on Lamar Miller, the team’s leading rusher with 330 yards on 63 carries. Miller has not topped 15 carries in a game this season and did so just four times in 16 games last season.