Vikings corner Jeff Gladney -- a star rookie for Minnesota in 2020 -- has just been indicted on a felony domestic violence charge ... and his football future is now very much up in the air.

Gladney was accused of violently beating his girlfriend in the Dallas area back in April ... after cops say the couple got into an argument over the contents of the woman's cell phone.

According to court docs, Gladney's accuser told officials the football player snapped after he found something on her phone ... hitting her, choking her, and dragging her by her hair across the ground.

Gladney was eventually arrested and posed for a mug shot.

It took several months, though, for a grand jury to hear the case ... but on Tuesday, it was revealed they indicted Gladney on a felony charge of third-degree family violence assault.

It's a VERY serious matter for the NFL player -- who's been away from the Vikings since his arrest -- because if convicted, Gladney faces up to 10 years behind bars.

With the case now moving forward -- potentially even resulting in a trial -- Gladney could now be asked to stay away from the Vikings indefinitely ... or even find himself cut from the roster.

Gladney is also facing a civil lawsuit from his accuser, who filed docs in court last month seeking $1 million in damages.

In her suit, the woman says after Gladney was violent with her, he "attempted to bribe, threaten, blackmail, and manipulate" her to keep quiet about it all.

Gladney has not publicly commented on the allegations.

The former TCU star -- a Vikings first-round pick in the 2020 NFL Draft -- started 15 games for Minnesota last season, recording 81 total tackles and 3 pass breakups.