Don Newcombe, second from right, at the 1949 All-Star Game with, from left, Roy Campanella, Larry Doby and Jackie Robinson. (AP)

Don Newcombe, an early African American pitching star who helped integrate major league baseball and whose struggle with alcoholism led him to become one of the first ex-players to lead a team’s substance-abuse program, died Feb. 19. He was 92.

His death was announced by the Los Angeles Dodgers, with whom he was associated for many years. The immediate cause was not disclosed.

Mr. Newcombe was a Dodgers mainstay alongside black stars Jackie Robinson and Roy Campanella on one of the best teams of baseball’s post-World War II heyday. He was major league baseball’s first successful black starting pitcher, helping clear a path for Hall of Famer Bob Gibson and two-time all-star Jim “Mudcat” Grant, among others.

An imposing right-hander at 6-foot-4 and 225 pounds, Mr. Newcombe was the only player to win the Rookie of the Year, Most Valuable Player and Cy Young awards before Justin Verlander, then with the Detroit Tigers, matched the feat in 2011.

Despite his success, Mr. Newcombe was dogged by shortcomings on and off the field. Unlike Robinson and Campanella, he never made the Hall of Fame; he failed to win a World Series game in five tries; he lost two years of his prime in the military; and he drank heavily, which he blamed for prematurely ending his career.

Mr. Newcombe later became an outspoken voice against alcohol abuse and an ardent supporter of those suffering from it. But he remained angry at the treatment he and other black major leaguers received from fans, opponents and teammates before and after Robinson broke baseball’s color barrier in 1947.

Don Newcombe in 2013. (Mark J. Terrill/AP)

Mr. Newcombe pitched for the Newark Eagles of the Negro leagues for two years before he was picked to start an exhibition game against a team of white major leaguers in 1945. In the third inning, having allowed no hits, he hurt his elbow and had to leave the game.

He cried in the dugout, worried that he had missed his chance to impress big league scouts. The Brooklyn Dodgers’ Clyde Sukeforth, however, sought him out, arranging for him to meet Dodgers president and general manager Branch Rickey.

“I didn’t even know who Branch Rickey was,” Mr. Newcombe later quipped.

Mr. Newcombe signed a contract with the Dodgers and accepted a $1,000 bonus.

Some scouts believed that his powerful arm and skill as a batter would make him the first black big leaguer, but Rickey figured Robinson — an Army officer who had spent four years in college — would better withstand the intense scrutiny of fans, sportswriters and opposing players. Mr. Newcombe, who was at Ebbets Field in Brooklyn for Robinson’s debut in 1947, did not begrudge the choice.

“Jackie was the only man I knew who could have put up with what he did and play baseball the way he did,” he told The Washington Post in 2013.

Other black players joined big league teams, and Campanella made the jump to Brooklyn in 1948. But Mr. Newcombe remained in the minor leagues, pitching for Dodgers affiliates in Nashua, N.H., and Montreal. The team’s front office remained wary of his youth and temperament.

“I think he can pitch in the majors, but he might undo everything [Robinson and Campanella] have accomplished,” Dodgers manager Burt Shotton told sportswriter Wendell Smith, who chronicled the emergence of black major leaguers.

Like other black players in baseball’s “great experiment,” Mr. Newcombe was expected to show restraint. In a 1948 game in Syracuse, N.Y., when he was with the Montreal Royals, an opposing batter charged the mound. One of his teammates — future television star Chuck Connors — stepped in to help Mr. Newcombe.

“He can’t fight you,” Connors reportedly told the opponent, “but I can.”

In May 1949, Mr. Newcombe made his debut in St. Louis against an all-white Cardinals team. The crowd was largely divided along racial lines, with black fans rooting for the Dodgers.

He struck out the first batter he faced, to loud applause. “Then I gave up four straight hits,” he told Sports Illustrated in 1955. “That taught me in a hurry that the majors were different.”

Off the field, the pressure was even more intense. Hotels were segregated, and fans often hurled vicious verbal abuse and threats at black players.

Almost two decades later, the Rev. Martin Luther King Jr. visited Mr. Newcombe’s Los Angeles home and told him how he and other African American players helped prepare the country for the civil rights era.

“He said to me, ‘Don, I don’t know what I would’ve done without you guys setting up the minds of people for change,’ ” Mr. Newcombe told Time magazine. “ ‘You, Jackie, and Roy will never know how easy you made it for me to do my job.’ Can you imagine that? How easy we made it for Martin Luther King!”

Donald Newcombe was born June 14, 1926, in Madison, N.J., and grew up in Elizabeth, N.J. His father was a private chauffeur, and his mother was a homemaker.

A self-described “indifferent” student, Mr. Newcombe dropped out of high school rather than retake biology. He began pitching in local leagues in his teens.

In 1949, his first season with the Dodgers, Mr. Newcombe won 17 games, with a league-best five shutouts, and was named the National League’s Rookie of the Year. In 1950, he won 19 and then had his first 20-win campaign in 1951.

On Oct. 3, 1951, he was the starting pitcher in one of baseball’s most memorable games: the finale of a three-game playoff to determine whether the Dodgers or New York Giants would play in the World Series.

Mr. Newcombe pitched the Dodgers to a 4-1 lead before giving up a run in the bottom of the ninth inning. There were two runners on base and one out when manager Charlie Dressen replaced him with Ralph Branca. Mr. Newcombe headed to the showers rather than watch from the bench.

“I heard this yell,” he told Sports Illustrated in 1955. “It was like an explosion. . . . I said to myself, oh, oh.”

The Giants’ Bobby Thomson had hit Branca’s second pitch for a pennant-winning home run, still hailed as baseball’s “shot heard round the world.”

Mr. Newcombe was drafted into the Army during the Korean War and spent two years training recruits at Fort Pickett, Va. After a season of readjustment, he won 20 games in 1955, the only year Brooklyn won the World Series.

The next year, after winning 27 games, Mr. Newcombe received the first Cy Young Award as baseball’s top pitcher — then presented to only one pitcher in the major leagues — and was named the National League’s Most Valuable Player.

One of the Dodgers’ sponsors kept a stocked cooler of beer in the locker room, and Mr. Newcombe often finished six cans before heading home after games. As his performance declined, he began to pack hard liquor for the team’s road trips.

After he retired in 1960, Mr. Newcombe said he figured that alcohol cost him “four or five” playing years. During his 10 years in the major leagues, he played on four all-star teams and had a record of 149-90, with a 3.56 earned run average.

His drinking continued unabated, and by the mid-1960s, he had lost the bar and liquor store that he owned. Gambling debts compelled him to pawn his 1955 World Series ring. His first marriage ended in divorce.

He woke one day in 1966 to find his second wife and their children with suitcases packed, about to leave. Mr. Newcombe begged for “one more chance” and quit drinking cold turkey.

In 1970, the Dodgers tapped him to start the team’s community relations department. Team President Peter O’Malley, who had bought Mr. Newcombe’s pawned World Series ring, returned it to him. In 1978, the Dodgers asked Mr. Newcombe to run their drug- and alcohol-abuse program.

In 1994, Mr. Newcombe sued the Coors brewing company for $100 million, alleging that it misappropriated his likeness in a Sports Illustrated advertisement for its Killian’s Irish Red beer. Mr. Newcombe argued that the ad was based on a 1949 photograph of him on the mound and that its use in a full-page beer advertisement was defamatory because of his struggles with alcohol. After years of legal wrangling, the case was settled out of court. It is often cited in other cases in which celebrities seek to retain control over the use of their images.

Mr. Newcombe’s first two marriages, to Freddie Cross and Billie Roberts, ended in divorce. Survivors include his third wife, the former Karen Kroner, and several children. A complete list of survivors was not immediately available.

He remained part of the Dodgers organization for the rest of his life and was a nattily attired fixture at home games into his 90s. After Barack Obama was elected president in 2008, Mr. Newcombe mailed him a signed baseball and letter congratulating him for breaking another kind of color barrier.

“I realize you’ll have some hard times,” the letter read, “but you’ll get through them.”