One of the most important keys to a successful baseball career is health. Even the mildest of injuries can sideline a player for weeks or even months.
Potential can be wasted, talent can be squandered, and even entire years of one's playing days can be gone in the blink of an eye.
Let's look at the four greatest careers that were defined by injuries.
The luckiest man on the face of the earth.
One of the greatest hitters the game has ever seen, Gehrig's career was cut short at the age of 36 by the disease that would eventually bear his name.
Imagine what Gehrig could have done in three or four more seasons with the Yanks.
Known for his dominant, yet abbreviated career, Sandy Koufax is still remembered as one of the greatest starters of all-time.
One morning before the 1965 season began, Koufax awoke with massive internal hemorhaging in his pitching arm.
He went on to pitch the entire 1965 and 1966 seasons in constant elbow pain. In those two years, however, Koufax led the league in wins, ERA, innings, strikeouts, and complete games.
He was forced to retire at the age of 30 having already won 3 Cy Young awards and the 1963 MVP.
Ken Griffey, Jr. could have made a very realistic run at Hank Aaron's home run record had he stayed healthy and with any luck, might have even reached 800.
Any shot at those goals, however, came to a crashing halt when he had three consecutive season-ending injuries from 2002-2004.
Add to that a partial tear and eventual hamstring rupture, and Griffey's career was never quite the same.
The main reason Mickey Mantle is No. 1 on this list is that he may have never played a game at full strength.
His knee problems began in high school and continued throughout his career.
During his rookie season, Mantle tore everything in his knee. He quite possibly even played his entire career on an unrepaired torn ACL (surgical ACL repair wasn't an option in Mantle's days).
Combine his knee problems, a hip injury and self-induced liver/stomach problems, and it's a miracle that Mantle could even play.
Think what this Triple Crown Winning, three-time MVP, and seven-time World Series Champion could have done if he was healthy.