Steve Howe, star relief pitcher of the Los Angeles Dodgers thought to have overcome a drug and alcohol problem, has been readmitted to a drug rehabilitation center at his request, the club announced yesterday.

Howe, 25, did not show up for the Dodgers' home game with the Giants Saturday and later in the day notified the team that he needed help.

"Steve is going through a very trying period . . . ," General Manager Al Campanis said, "and we want to do everything we can to help him to a full recovery. Arrangements were worked out (Saturday night) to admit Steve to a treatment center . . . He's already committed. We can't tell you where."

In 14 games this season, Howe has allowed no earned runs in 22 1/3 innings and has a 2-1 record with a National League-leading seven saves. His 1983 salary is $325,000.

Howe spent Nov. 21-Dec. 28 at The Meadows rehabilitation center in Wickenberg, Ariz., for a cocaine and drinking problem . . .

The Cincinnati Reds have called off the three-day suspension without pay imposed on outfielder Cesar Cedeno last week. Had the discipline stood, Cedeno would have lost about $13,000 of his estimated $700,000 salary.

Cedeno had been suspended after tearing up his ticket and refusing to fly with the team from Chicago to Cincinnati because he would not have a first-class seat. The Reds said Cedeno still "has been fined an undisclosed amount," but the players association has dropped its grievance on Cedeno's behalf.

Cedeno made his first start yesterday since May 12 . . .

Tom Estepp of Springfield broke a 5-5 tie with a one-out single in the top of the ninth to lead James Madison to a 6-5 win over Delaware in the finals of the East Region of the NCAA Division I tournament. The Dukes (37-11) have won four straight and will meet Texas in the first round of the college World Series Friday in Omaha, Neb.

Estepp, who attended Lee High School, scored Mike Reeves of Falls Church, who had walked. Jack Urban led James Madison offensively with three singles and two RBI, and pitcher Andy Heintzleman (2-1) earned the win after coming on in relief in the eighth inning . . .

The Home Plate Club has named Greg Hall, Prince George's Community College freshman catcher from Laurel, its all-Metropolitan junior college player of the year; Jim McNamara of Madison and David Vaughan of Bowie its high school MVPs.

Presentations were made at the HPC dinner during which the club's inaugural all-Met college team (announced last week) was recognized. Hall's presenter was Donald Redmiles, retiring after 30 years of high school and college coaching in the area, the last 14 at PGCC.

The HPC-administered Clark Griffith League for players age 17-19 begins its 37th year today, with seven clubs, at the George Mason U. North field in Fairfax.