Gaetti played collegiate baseball for
Lake Land College in
Mattoon, Illinois, and
Northwest Missouri State University. Gaetti was drafted three times before finally signing with the
Twins — first by the
St. Louis Cardinals in the fourth round of the
1978 Major League Baseball draft (then held annually in January) and again in 1978 by the
Chicago White Sox in the third round of the June secondary draft before he was drafted by the Twins in the first round of the June secondary portion of the
1979 draft. Gaetti signed on June 21, 1979. Gaetti then spent the next three years in the Twins' minor league system, playing for the rookie level
Elizabethton Twins in the
Appalachian League in 1979, the A-level
Wisconsin Rapids Twins in the
Midwest League in 1980, and the AA-level
Orlando Twins in the
Southern League in 1981. Gaetti then made his major league debut in nine September games and he hit a home run off of
Charlie Hough in his first major league at-bat. In 1982, Gaetti would become a permanent fixture at third base for the Twins and would man third base in Minnesota for the next nine seasons. In 1986, Gaetti batted .287 with 34 home runs and 108 runs batted in. Gaetti won four consecutive
Gold Glove Awards for fielding excellence from 1986 through 1989. Gaetti helped propel the Twins to the post-season and their first World Series championship, hitting .257 with 31 home runs and 109 RBI. He also hit himself into the record books, with home runs in his first two career postseason plate appearances in the
American League Championship Series to help the Twins upset the
Detroit Tigers. Gaetti was selected as an
All-Star in 1988 and 1989. Playing against the
Boston Red Sox on July 17, 1990, Gaetti helped the Twins become the only team in baseball history to turn two triple plays in the same game. Despite their defensive heroics, the Twins lost the game 1–0. His production at the plate would decline and after hitting only .229 in , Gaetti left the Twins for the Angels as a
free agent. His production continued to drop off with the Angels and midway through the third year of his four-year contract, he was released, in June . He was almost immediately signed by the Royals, who had lost their projected regular third baseman,
Keith Miller, to injury and had been playing rookie
Phil Hiatt at third. Gaetti hit 26 home runs for the Royals in 665 at-bats between 1993 and 1994, splitting time at third with Miller,
David Howard, and
Terry Shumpert. In , Gaetti played in 137 games and at the age of 36, he hit .261 with 35 home runs and 96 RBI, winning his only Silver Slugger, Gaetti was used as an emergency relief pitcher by both the Cardinals and the Cubs, retiring with an ERA of 7.71 and one strikeout in three appearances. Gaetti finished in the top 25 voting for American League Most Valuable Player four times in his career, three times with the Minnesota Twins (1986–1988), and once with the Kansas City Royals (1995). He finished fifth in American League Rookie of the Year voting (1982). He was a four-time Golden Glove Award winner (1986-1989). With seven defensive
triple plays in his career, Gaetti is tied with six other players for the third-most triple plays in a career.
Jake Beckley and
Germany Smith both had eight, while
Donie Bush,
Bid McPhee, and
John Morrill all share the record at nine. ==Retirement==