NFL lineman D.J. Fluker claims his ex-girlfriend kidnapped their daughter earlier this month — and he’s concerned things could get worse.

Here’s the deal … Fluker claims his ex, Kimberly Davis, was supposed to have a supervised visit with their daughter and Fluker’s sister on Sept. 19, while the Baltimore Ravens offensive lineman was away in Houston to play the Texans.

But, Davis allegedly kicked Fluker’s sister out of the apartment and refused to return the child back to D.J. Fluker reportedly told Davis she did NOT have permission to keep their daughter overnight but Davis still wouldn’t hand over the kid.

So, 29-year-old Fluker called police — but Davis still refused to return the child.

Finally, cops arrested Davis on Sept. 22 and now she’s facing a charge of kidnapping a child younger than 16 years old.

If convicted, Davis faces up to 30 days in jail and a $250 fine. She’s since been released from custody.

Fluker told cops he’s in “fear for the safety of our daughter” and added, “I don’t feel safe during this time,” according to The Baltimore Sun.

Davis was arrested back in July after allegedly punching Fluker in the nose during a dispute. She was charged with 2nd-degree assault for that incident.

Fluker — 6’5″, 340 pounds — was the 11th overall pick in the 2013 NFL Draft after dominating at Alabama. He’s played for the Chargers, Giants, Seahawks and Ravens.