The Steelers cut the troubled 24-year-old following his arrest on a battery charge in Gainesville, Fla., on Thursday, the latest in a series of off-the-field incidents that have threatened his career.
Gainesville police officers charged Rainey with a single count of misdemeanour simple battery after an altercation with his girlfriend. Police said in a news release the two were arguing over Rainey's cellphone. When his girlfriend got into a vehicle, the former Florida Gator tried to pull her out.
Witnesses told detectives that Rainey slapped his girlfriend across the face and then chased her when she ran away with his phone in her purse.
The Steelers, who selected Rainey in the fifth round of the 2012 NFL Draft, waived shortly after being made aware of his arrest.
"Chris Rainey's actions this morning were extremely disappointing," general manager Kevin Colbert said. "Under the circumstances and due to this conduct, Chris will no longer be a member of the Pittsburgh Steelers."
Rainey worked primarily on special teams during his rookie season. He averaged 26.5 yards on 39 kickoff returns. The Steelers used him occasionally as a change of pace in the backfield. Rainey finished with 102 yards rushing and two scores while also catching 14 passes for 60 yards.
Rainey's agent, Joel Segal, didn't return a phone call for comment.
Thursday's arrest wasn't Rainey's first brush with the law. He was arrested Sept. 14, 2010 and charged with aggravated stalking, a third-degree felony, for allegedly sending a former girlfriend a threatening text message that read, in part, "Time to die ...."
Rainey spent a night in jail and was dismissed from the team by coach Florida coach Urban Meyer the next day, after Meyer said Rainey violated the program's core value regarding violence against women. Rainey agreed to a plea deal two weeks later and eventually returned to the field.