Jackie Jensen, the American League's most valuable player in 1958, died of an apparent heart attack early yesterday at the University of Virginia Hospital in Charlottesville. He was 55 years old.
Jensen, a blond, husky Californian who began his 11-year major league career with the Yankees, also played for the Washington Senators and the Boston Red Sox. He starred in football at the University of California, running 67 yards for a touchdown in the 1949 Rose Bowl, and later married a national diving champion. When he joined the Yankees in 1950, he was called The Golden Boy.
Yet, some aspects of his career were not so golden. He failed with the Yankees and they traded him. He developed a fear of flying that neither psychiatrists nor hypnotists could cure. And he often said he wanted to quit baseball to be with his family. Married a Diving Star
Jack Eugene Jensen first met Zoe Ann Olsen in 1944, when she was a 13-year-old diving prodigy in Oakland, Calif., and he was a 17-yearold high school athletic hero. He served in the Navy near the end of World War II, then went to the University of California, where he was an all-America fullback.
He left after his junior year to take a $40,000 bonus and join Oakland of the Pacific Coast League in 1949, when he and Miss Olson were married. After one season there, his contract was purchased by the team he had always preferred, the Yankees. They hoped he would eventually replace Joe DiMaggio, then in his final years as the center fielder.
When DiMaggio retired after the 1951 season, Jensen was supposed to compete with Mickey Mantle for the center-field job. But on May 3, 1952, the Yankees traded him and three others to Washington for Irv Noren, an outfielder. He batted .171 in 45 games as a Yankee in 1950, and .298 in 56 games in 1951.
With the Senators, he hit .286 and .266 in two seasons, then was traded to Boston for Mickey McDermott and Tom Umphlett. The trade took some pressure off him because in Boston he was always secondary to Ted Williams. Batted Cleanup for Boston
From 1954 through 1959, Jensen batted fourth for the Red Sox and swatted line drives at Fenway Park's short left-field wall. He drove in 667 runs in six seasons, including 122 in 1958, when he was voted the league's most valuable player.
After the 1959 season, he quit baseball and went home to Lake Tahoe, Nev. But he came out of retirement and rejoined the Red Sox in 1961. He jumped the club during a trip in April, but came back and finished the season, batting .263, with 66 runs batted in. He then retired for good, with a career batting average of .279.
His first venture after baseball was to buy a share of the Ponderosa Golf Course in Truckee, Calif. He later sold his share, as well as his share in a restaurant. In 1966, he became sports director of KTVN, a Reno radio station. He also did commentary for ABC at college football games.
In 1968 he and his wife were divorced. Later that year he married Katherine Cortezi and became assistant baseball coach at the University of Nevada at Reno. The following year he became head coach.
He went on to coach at California, where he was dismissed in 1976.Before he was stricken yesterday at his home in Fork Union, Va., he complained of fatigue. He had recently returned from a baseball camp he ran annually for youngsters, according to his wife,
Besides his wife, he is survived by two sons, Jon and Jay, both of Reno; a daughter, Jan Knapp of Carson City, Nev., and a stepdaughter, Kay Tinsley Place of Washington.
Illustrations: photo of Jackie Jensen