The Dolphins released running back Mark Walton after the team was made aware of a "police matter" on Tuesday morning, general manager Chris Grier said in a statement.
"We hold our players to a high standard and take these matters very seriously. We will have no further comment at this time," Grier said.
The Sun-Sentinel reports Walton was arrested at 4:15 a.m. ET in Davie, Fla. after he punched a woman who was five weeks pregnant with his child. Walton reportedly pushed her against a wall and punched her multiple times in the face causing her left eye to swell. A police document obtained by ESPN reported Walton was charged with the aggravated battery of a pregnant woman.
According to The Sun-Sentinel, Walton reportedly learned of the pregnancy two days before his arrest.
Walton's agent did not immediately return a message from ESPN for comment.
Walton was nearing the end of the four-game suspension he received from the NFL for violating its conduct and substance abuse policy. The suspension was related to his three offseason arrests between January and March.
During his suspension without pay, Walton was allowed to attend team meetings and be in the Dolphins' facility but could not practice. He was eligible to return on Dec. 2 after Miami's Week 13 game against the Eagles.
In August, Walton received six months of non-reporting probation as part of a plea deal to resolve his three offseason cases. His probation was vacated after he met the court's conditions.
Following an arrest in March, Walton was facing a felony charge for carrying a concealed weapon, and misdemeanor charges for possession of marijuana, reckless driving and resisting arrest. He was able to get those charges reduced.
He also had charges dismissed for a drug charge after his January arrest and a battery charge after his February arrest.
The Bengals, who drafted Walton in 2018 from Miami, cut him in the offseason following his third arrest. The Dolphins signed him in May but said there would be a zero-tolerance policy. It appears the team stayed true to its word. Through seven games this season, Walton recorded 53 carries for 201 yards.