A police officer was blunt with Vontae Davis during his DUI arrest on Saturday ... telling the ex-NFL star straight up, "You almost killed somebody."

The stern chat with Davis was captured on Florida Highway Patrol dash cam footage, obtained by TMZ Sports, after officers said the two-time pro bowler had crashed his Tesla into another car during a wreck on a highway at around 7:50 a.m.

In the video, you can see Davis appeared to be dozing in and out of consciousness as officers attempt to question him about the leadup to the accident.

They asked him where he had been, if he had been drinking, if he was injured, and if he'd submit to field sobriety tests. Davis answered some of the questions -- others not so much. He seemed to be slurring some of his words during his replies.

At one point, the video shows he told a cop he had been to a club and had consumed two "mixed drinks" prior to getting behind the wheel. He said he left the venue at around 2 a.m., and had no recollection of a car crash.

Officers eventually told him he was under arrest -- and when Davis asked why, one of the cops didn't mince words.

"Your eyes are bloodshot," he said. "Your speech is slurred. You can barely stay awake. All right? You almost killed somebody."

When Davis said he "didn't almost kill nobody" -- the officer responded, "Yeah, man. They were in a truck on the side of the road. You took them completely out. And there was a father and son there on the shoulder."

Davis, who played 10 seasons in the NFL with the Colts, Dolphins, and Bills, was ultimately arrested and booked for DUI.