The Cardinals have deactivated Dwyer from all team activities.
According to the AP, Phoenix police said Dwyer was arrested on charges of domestic violence and aggravated assault for two altercations at his home in late July involving a 27-year-old woman and an 18-month-old child. One of the counts was "aggravated assault causing a fracture."
AZCentral reports that Dwyer was also charged with preventing the use of a phone during an emergency and that the woman left the state with the child shortly after the incident. A police spokesman said investigators took a report on the incident on Sept. 11 and detectives have been seeking out-of-state medical records and interviewing witnesses.
Dwyer denied any physical assaults in his interview with detectives, according to AZCentral.
From a statement by the Cardinals:
"We became aware of these allegations this afternoon when notified by Phoenix police and are cooperating fully. Given the serious nature of the allegations we have taken the immediate step to deactivate Jonathan from all team activities. We will continue to closely monitor this as it develops and evaluate additional information as it becomes available."
An NFL spokesman said Dwyer’s situation will be reviewed under the NFL’s Personal Conduct Policy, according to Ian Rapoport of NFL.com.
Dwyer's reported arrest comes as the league faces heavy scrutiny over its handling of domestic violence cases.
Dwyer, 25, is listed as the No. 2 running back on the Cardinals' depth chart. He has rushed for 51 yards and a touchdown on 16 carries over two games this season.
He signed with Arizona this offseason after spending the first four seasons of his career with the Pittsburgh Steelers.
The Cardinals (2-0) host the San Francisco 49ers on Sunday.
- Chris Johnson, Sarah Barshop and Molly Geary