Greenwell was a leading contender for the American League MVP award in 1988, but lost to Jose Canseco, who had the first 40 home run, 40 stolen base season in baseball history.

[2] Throughout his Red Sox career, Greenwell suffered under the weight of lofty expectations for a Boston left fielder, as since 1940 the position had been occupied by Ted Williams, Carl Yastrzemski and Jim Rice — all MVP winners, regular triple crown candidates, and eventual members of the Baseball Hall of Fame.

Although his play rarely reached the level of his predecessors, he provided a solid and reliable presence in the team's lineup for several seasons.

[12] His career in the major leagues heightened expectations from Japanese fans, but he left the team during spring training and returned to the United States; he had suffered a herniated disc when diving for a ball.

[15] However, Greenwell suddenly announced his retirement after appearing in just seven games; he had fractured his right foot with a foul tip, and the injury would have prevented him from playing for at least four weeks.

[18] Greenwell was also the interim hitting coach for the Reds in 2001, filling in when Ken Griffey Sr. was given a medical leave of absence.

[19][20] Upon his retirement from baseball, Greenwell began driving late model stock cars at New Smyrna Speedway, winning the 2000 Speedweeks track championship.

[21] In May 2006, he made his Craftsman Truck Series debut at Mansfield Motorsports Park for Green Light Racing, starting 20th and finishing 26th.