Lavagetto was born in Oakland, California. Nicknamed "Cookie" after an owner of the Oakland Oaks, his first professional team, he played ten seasons in the National League with the Pittsburgh Pirates and Brooklyn Dodgers, missing four full seasons due to World War II service in the United States Navy. A, right-handed batter and thrower, he hit.269 with 945 hits in 1,043 games, including 183 doubles, 37 triples, and 40 home runs. His best season was, when he hit.300 with 87 runs batted in for Brooklyn. On October 3, 1947, at Ebbets Field, Bevens was ahead 2–1 going into the bottom of the ninth inning, and got two outs. He had surrendered no hits — an unprecedented World Series achievement at the time — but two runners were on base from Bevens' ninth and tenth walks of the game. Lavagetto was summoned by Dodger pilot Burt Shotton to hit for Eddie Stanky, and with no balls and one strike cracked an opposite-field double off the right field wall to break up the no-hitter and score the two Dodger runners for a 3–2 Brooklyn win. It was Lavagetto's only hit of the series, and his last as a major league player.
Return to minors and major league coach
After being released by the Dodgers following the 1947 Series, Lavagetto returned to Oakland to finish his playing career with the Oaks. When Oakland manager Chuck Dressen was named the field leader of the Dodgers in 1951, Lavagetto accompanied him and returned to Brooklyn as one of his coaches. He was an aide to Dressen with Brooklyn and the Pacific Coast League Oaks, and followed him a third time as a member of the coaching staff when Dressen became manager of the Washington Senators in.
Senators'/Twins' manager
On May 7, 1957, with the Senators foundering in last place, Dressen was fired and Lavagetto named as his successor. The team improved slightly, but finished last in, and. Finally, in, Lavagetto's Senators rose to fifth place in the eight-team American League. The club featured promising young players such as Harmon Killebrew, Jim Kaat, Earl Battey and Bob Allison, as well as veteran pitcher Camilo Pascual, just entering his prime. However, the Senators' encouraging 1960 season came too late to keep the franchise in Washington; owner Calvin Griffith moved the club to Minneapolis–St. Paul, where it became the Minnesota Twins in 1961. Lavagetto was the first manager in Twins history, but did not finish the season. With the Twins mired in ninth place in the new ten-team AL, he took a seven-game leave of absenceJune 5 and then returned to the helm on the 13th, but was fired on June 23 with the club still in ninth place. He was replaced by coach Sam Mele, under whom the Twins became pennant contenders in 1962 and pennant winners in 1965. Lavagetto, as manager for the so-called "Griffs", won 271 and lost 384.