NFL rookie Christian Kirk was showing signs consistent with cocaine use when he was arrested at a golf tournament in Arizona back in February ... this according to the police report obtained by TMZ Sports.
Kirk -- a 2nd round draft pick by the AZ Cardinals -- was arrested for criminal damage to a car on Feb. 3rd after cops say he was throwing rocks at cars in a parking lot outside of the Phoenix Open.
Event security had contacted police and said the suspects were "high."
When the Scottsdale PD arrived to the scene, one of the officers "immediately noticed Krik's demeanor.