Lynn started his career with a phenomenal 1975 season in which he won the American League Most Valuable Player and Rookie of the Year awards, led the league in doubles, runs scored, and slugging percentage, finished second in the league with a .331 batting average, and won a Gold Glove award for his defensive play in center field. His MVP-Rookie of the Year double was the first in Major League Baseball history, and has only been duplicated once (by Ichiro Suzuki in the AL in 2001).
However, Lynn rarely duplicated his early success. He was hampered by injuries sometimes caused by reckless play--such as a broken rib caused by crashing into an outfield wall, or knee injuries from breaking up double plays--but more often simply of the nagging variety, such as strains and sprains. When Lynn signed with the Baltimore Orioles as a free agent following the 1984 season, one newspaper report criticized Lynn saying, "He could pull a hamstring while taking a shower." Lynn never once played more than 150 games in a season and only topped 140 games four times.
Longing to play in California where he had grown up, the Red Sox traded him to the Angels after the 1980 season. However, away from Fenway Park, which was friendly to left-handed hitters like Lynn, he never hit over .300 again. Lynn did go on to hit more than 20 home runs in six consecutive seasons starting in 1982, and in 1983 he hit the only grand slam home run in All Star Game history. His four home runs in All Star games is second only to Stan Musial.
Following the 1984 season, Lynn signed a lucrative contract with the Baltimore Orioles, who signed numerous free agents in the mid-1980s in an ultimately unsuccessful effort to win another World Series. The Detroit Tigers acquired Lynn for their 1988 pennant drive, which also proved unsuccessful. Following a disappointing 1989 season, Lynn wrapped up his career with one season with the San Diego Padres, retiring at the age of 38 with career statistics that only hinted at his early potential.