That could change if details emerge showing aggravating circumstances.
According to KPAX News, Johnson refused to take a breath test after an officer stopped him for driving in the dark without use of headlights.
Johnson's arrest comes less than two years after officers arrested him for getting "out of control at a party" in an incident authorities described as alcohol-related, one in which officers used a taser to subdue Johnson and one of his then-teammates at the University of Montana.
Johnson, one of three cornerbacks on the Rams' roster, played about one-third of the defensive snaps as a rookie third-round choice last season. He figures prominently into plans for the future along with starters Cortland Finnegan and Janoris Jenkins. Johnson played at Montana with Rams coach Jeff Fisher's son.
The NFL generally does not suspend first-time offenders of its policy relating to alcohol abuse in the absence of what it calls aggravating circumstances. Johnson, with no known alcohol-related incidents since entering the NFL, would appear more likely to incur a fine of two game checks.
"We are aware of the situation regarding Trumaine Johnson," a statement from the Rams read. "We are gathering more information and will have no further comment at this time."