Ellis, scheduled to stand trial next week, agreed to misdemeanor assault and battery during a pre-trial hearing.
The district attorney's office wasn't immediately available to comment on potential jail time, but the victim's attorney, S. Howard Woodson, told the Star-Ledger of Newark the plea deal means six months of active jail time.
Under Virginia law, Ellis would have to serve only 90 days, but time served could be applied.
Ellis' attorney, Timothy Clancy, confirmed to the New York Post that an agreement had been reached, but said it wouldn't be approved by the court until next week. Clancy disputed Woodson's claim about potential jail time, but didn't provide any specifics in the agreement.
Ellis apparently has avoided potential deportation. Because he's a non-U.S. citizen, Ellis -- born in Jamaica -- could have been deported with an aggravated felony conviction, according to immigration law.
The Jets declined to comment, referring questions to Ellis' lawyer.
The Jets were aware of Ellis' legal troubles when they selected him in the third round of the 2011 draft. An incident occurred on April 10, 2010, when he assaulted a fellow student on the Hampton campus. Ellis said he was defending his girlfriend, sources said.
Ellis, speaking to reporters on Wednesday in the Jets' locker room, declined to comment.
He's also facing a civil suit. It was filed last April by the victim, Dennis Eley, who is seeking $3 million in damages. In his complaint, obtained by ESPNNewYork.com, he accused Ellis of beating him unconscious and breaking his nose and jaw, requiring two surgeries.
Woodson recently withdrew the suit, but only after a technicality -- it was about to lapse under Virginia state law -- and he told ESPNNewYork.com late last week he intends to re-file.
Ellis played in only five games last season, recording six tackles. He's projected as a backup for the upcoming season.