Miami Dolphins star defensive back Xavien Howard was arrested just hours after his team beat the New England Patriots on Sunday ... cops say he roughed up his fiancee in an argument over a purse.

According to police documents obtained by TMZ Sports, Howard -- who missed the Fins' win over the Pats because of recent knee surgery -- got into an altercation with his baby mama at their Davie, Florida home late Sunday night.

In the docs, the woman -- who has three children with Howard -- claims the NFL player began arguing with her "over a recent purchase of a purse at a store that wasn't disclosed to her."

We know what you're thinking about the purse -- we're thinking it too -- but the report doesn't explain anything more than that.

The woman says the argument turned physical, the docs say Howard "grabbed both her arms and pushed her back up against the mirrored glass wall in the hallway of their bedroom."

The woman claims after 6-foot, 200-pound Howard let her go, she landed on one of Howard's crutches.

When cops arrived, they say they noticed she had "visible scratches and redness" on her arm as well as "redness and an abrasion" on her right elbow from falling onto Howard's crutch.

Responding officers believe there was enough evidence to make an arrest and took Howard into custody on a domestic battery charge.

Cops note Howard was NOT taken directly to jail because he complained of knee pain from his recent surgery. Officials took him to a local hospital first to be examined.

Once he received medical clearance, Howard was transported to jail where he was booked and posed for a mug shot.

The 26-year-old had been a star for the Dolphins prior to his knee injury this season ... making a Pro Bowl in 2018 and logging 12 career interceptions in 40 games.

Miami selected Howard in the 2nd round of the 2016 NFL Draft.