Chris Johnson -- 1st Pic After Being Shot ... With Warning to Gunman

Sporting a sling on his injured arm, NFL running back Chris Johnson posed for a photo for the first time since he was shot in the shoulder during a drive by shooting in Florida this weekend.

Johnson appears in the photo with two other men -- one of whom is sporting bandages on an injured arm ... and the other who is flipping off the camera.

The man with the double-bird is rapper Kenny Turner -- a friend of Johnson's who posted the pic and included a message that appears to be directed at the shooter.

"I HEARD YOU P*SSIES LOOKIN 4 me!!!!! WE GOT something in common....f*ck YA!!!! #juice."

As we previously reported, one of Johnson's friends was killed in the shooting -- and Johnson is not cooperating with police in the investigation.

Judging by Turner's message -- seems cops aren't the only ones on the hunt ...

11:38 AM PT -- Johnson just issued a statement on Instagram insisting the message is NOT a threat directed at the gunman.