St. Louis Cardinals linebacker E.J. Junior pleaded guilty yesterday in Tuscaloosa, Ala., to possession of cocaine and was sentenced to two years in prison and fined $200.

Junior, 22, a former University of Alabama player, was arrested April 6, 1981, during a raid at an apartment and charged with possession of cocaine and marijuana.

The guilty plea was made in a closed hearing before Tuscaloosa County Circuit Judge Claude Harris Jr., who sentenced Junior to the minimum two years in prison and accompanying $200 fine. "With respect to the jail sentence, we have applied for probation," said Junior's attorney, Robert B. Harwood, who said the probation hearing had been tentatively set for March 17 . . .

A county judge withdrew a 90-day jail term for Kansas City Royals Manager Dick Howser and his batting coach, Rocky Colavito, and placed them on six-month, unsupervised probation for a summer altercation with police.

On Oct. 12, Municipal Judge Leonard Hughes Jr. sentenced Howser and Colavito to jail for reportedly struggling with officers after an Aug. 19 auto accident outside Royals Stadium.

The incident in which Howser and Colavito were charged occurred following a game between the Royals and the Chicago White Sox. A car driven by Colavito left a gate at the Truman Sports Complex to enter a major thoroughfare and was struck by a southbound car driven by a 19-year-old man.

An argument between Colavito and the driver of the second car, David L. Roach, followed and when an officer arrived he attempted to break it up, police said. Then a scuffle began involving one or more officers, Colavito and Howser, a passenger in Colavito's car.