The caller ID'ed himself as Frank from Porsche Emergency Center ... and he told police that he was on the phone to "report a car accident for one of our customers" in Medina, Ohio.

The caller was asked if there was anyone hurt in the accident -- and he said yes, telling them that "a lady" had sustained injuries to her head. He requested for both police and EMS to go out to the scene.

A second man also called 911 to report the crash ... telling dispatch he had seen "a bad accident over here."

"A girl left her car over here," the caller said, adding, "It's just one car. They lost control over here. They're both sitting outside."

The caller also told dispatch that the wreckage at the scene was gnarly.

"They flipped this thing, I do believe," he said. "They tore it up."

Cops say they eventually arrived at the scene at 2:58 PM ... and discovered a gray Porsche 911 Turbo S off the road that had significant damage to it.

Police say Garrett was ID'ed as the driver -- and he was transported to a nearby medical facility with non-life-threatening injuries. They say his female passenger was also taken to a local hospital with non-life-threatening injuries.

Cops do not believe alcohol or drugs were involved in the accident. A spokesperson for the Ohio State Highway Patrol tells us, "A blood draw for the purposes of law enforcement was not conducted due to a lack of probable cause as signs of impairment were not observed by the investigating trooper."

NFL Network's Tom Pelissero reported Tuesday that Garrett crashed his car in an attempt to swerve out of the way of an animal on the road.