Andrew H. Warren, the Florida State Attorney for Hillsborough County, stated the charge was dropped Wednesday following his office's review of the criminal report affidavit detailing the incident, per court records obtained by NFL.com.
TMZ first reported the development.
Foster's Nov. 24 arrest in Tampa led to the linebacker being released by the San Francisco 49ers hours before their Week 12 game against the Buccaneers. He was claimed off waivers by the Redskins three days later and placed on the Reserve/Commissioner Exempt List by the NFL -- a move that prevents the linebacker from playing until the league's investigation into Foster has been completed.
Under the league's personal conduct policy, players can be disciplined by the NFL even if they are not charged or convicted of a crime.
"We are monitoring all developments in the matter, which continues to be under review by the league," NFL spokesman Brian McCarthy said in a statement.
Elissa Ennis, the alleged victim, told police that during a verbal altercation with Foster, he slapped her phone out of her hand, pushed her in the chest area and slapped her with an open hand on the right side of her face. Officers observed a one-inch scratch on her left collarbone, according to police.
During their initial investigation of the incident, officers learned Foster and the victim lived together in the past and they were involved in an on-again-off-again relationship over the past three years.
Foster has had multiple run-ins with the law since being drafted by the 49ers 31st overall in 2017. He was charged in January in Alabama with second-degree marijuana possession. That charge was eventually dismissed after he completed a first-time offender diversion course.
He then faced more serious charges for an incident in California in February. He was initially charged in April with felonies for domestic violence, making criminal threats and weapons possession after being accused of assaulting Ennis.
"There's no guarantee he's ever going to play here," Gruden said. "He's got a lot of work to do -- personally, with the team, with the NFL, with himself -- before he even thinks about playing football again."