A man in his late 40s was struck by a car before being taken to hospital with a head injury that is not believed to be life threatening.
The accident occurred just after midnight on Saturday morning at the junction of Bishops Road and Eastbourne Terrace just behind Paddington rail station in Central London.
The Metropolitan Police said the car involved failed to stop at the scene of the accident.
"A 33-year-old man was subsequently arrested by officers from City of London Police on suspicion of failing to stop at the scene of a road traffic collision and taken to a central London police station,” a police spokeswoman said.
"He has been bailed to mid-September pending further inquiries."
King, 33, was told he could leave the club on a free transfer earlier on Friday.