Sheffield was a first-round pick of the Brewers, who selected him sixth overall in the 1986 amateur draft after a standout prep career at Hillsborough High School in Tampa, Florida.

Because of his combination of skill, sportswriter Joe Posnanski wrote, "I can't imagine there has ever been a scarier hitter to face."

Sheffield was born in Tampa, Florida, and grew up in Belmont Heights, near the Ponce de Leon projects.

[3] After four seasons in Milwaukee, the Brewers traded Sheffield to the San Diego Padres for Ricky Bones, José Valentin, and Matt Mieske on March 26, 1992.

Sheffield faced his uncle Dwight Gooden for the first time in a Major League game on May 12, 1992, getting a hit in three at-bats.

In his first All-Star season, he contended for the Triple Crown for much of the year; while he missed out on the home run (33, two fewer than the leader, teammate Fred McGriff) and RBIs (100, nine fewer than leader Darren Daulton) titles, he won the National League batting title (the only one of the nine in Padre history not won by Tony Gwynn) with a .330 average.

On June 24, 1993, he was traded, with Rich Rodriguez, to the Florida Marlins for Trevor Hoffman, José Martínez and Andrés Berumen.

Sheffield hit 112 home runs with the Marlins from 1994 to 1998, including 42 in 1996, making the All-Star Game in 1996, and leading them to victory in the 1997 World Series against the Cleveland Indians.

[3] On May 14, 1998, he was traded along with Manuel Barrios, Charles Johnson, Bobby Bonilla, and Jim Eisenreich to the Los Angeles Dodgers for Mike Piazza and Todd Zeile.

But during the off-season, he began lobbying for a trade because he thought the Dodgers were spending their money stupidly and sliding in the wrong direction, and publicly criticized coaches and teammates.

[3] On January 15, 2002, Sheffield was traded to the Atlanta Braves for Brian Jordan, Odalis Pérez, and Andrew Brown.

On December 19, 2003, after negotiations between Sheffield and George Steinbrenner, a contract was agreed upon with the New York Yankees worth $39 million over three years.

[11] He joined a lineup that included Derek Jeter, Jason Giambi and the newly acquired Alex Rodriguez.

On July 27 Sheffield hit his 400th career home run off of Micheal Nakamura of the Toronto Blue Jays in the top of the 9th inning.

On April 14, 2005, a Red Sox fan leaned over the railing at Fenway Park and distracted Sheffield as he was going to field a ball hit by Jason Varitek.

[12] Sheffield started the 2006 season on pace for a .300 batting average and 30 homers, before he collided with Shea Hillenbrand of the Toronto Blue Jays on April 29, 2006.

"[14] On November 10, 2006, the Yankees traded Sheffield to the Detroit Tigers for minor league pitchers Humberto Sánchez, Kevin Whelan, and Anthony Claggett.

He was also one of only six batters in the AL to have at least 20 home runs and 20 stolen bases, along with Alex Rodriguez, Grady Sizemore, Ian Kinsler, B.J.

On September 8, 2008 in a game against Oakland, Sheffield hit the 250,000th regular season home run in Major League Baseball history according to Baseball-Reference.com.

On September 19, 2008, Sheffield was hit by a pitch from Cleveland Indians pitcher Roberto Heredia Hernández and walked to first base.

Hernández and Sheffield were both ejected, along with Indians catcher Víctor Martínez and Tigers second baseman Plácido Polanco.

Though he initially suggested he wanted to sign with a team for the 2011 season,[25] he announced his retirement at the beginning of 2011 spring training.

Sheffield states in his book, Inside Power, that he had no knowledge of the cream containing steroids, and had no reason to assume so at the time.

[34]: 121 In their book Game of Shadows, reporters Mark Fainaru-Wada and Lance Williams allege that Sheffield worked with and received steroids such as testosterone and human growth hormone from his and Barry Bonds's personal trainer Greg Anderson.

[36] On December 5, 1993, Sheffield was arrested after being clocked driving a Ferrari Testarossa 110 miles per hour (180 km/h) on Interstate 4 in Florida and failing a breathalyzer test.

[37] In October 1995, Sheffield was shot in his left shoulder after an attempted robbery when he stopped his car at a traffic light in Tampa.

[38] Throughout his career, Sheffield was verbal about his need for sufficient financial compensation and respect, demanding better pay when he was with the Dodgers, and refusing to play in the inaugural World Baseball Classic, saying the regular "season is when [he's] getting paid.

Deleon is a gospel recording artist and has sung the National Anthem at Yankee Stadium during a playoff game with Sheffield on the lineup.

[40] In February 2005, a man was arraigned in federal court on charges of extorting Sheffield by threatening to release a sex tape of Deleon with an ex-boyfriend.