5 NFL superstars whose careers were cut short due to horrible injuries 

#3 - Bo Jackson

Raiders running back Bo Jackson

Bo Jackson is one of the biggest "what if" players in NFL history. He was one of the greatest all-around athletes the world has ever seen. He produced at a high level in professional football and professional baseball, as well as being a track and field superstar.

Jackson averaged an incredible 5.4 yards per carry during his four-year career and was a touchdown threat from anywhere on the field. During his final game, he suffered a dislocated hip, which he claims he popped back into the socket so he could finish the game, which he did. He never played football again due to complications from the injury.

#2 - Sterling Sharpe

Former wide receiver Sterling Sharpe

Sterling Sharpe didn't miss a game during his seven-year career and was one of the most dominant wide receivers in the league. He led the NFL in receptions three times, and receiving touchdowns twice on his way to three first-team All-Pro selections. He is one of just four players since the official merger to win the receiving triple crown for a single season.

Sharpe suffered a devastating neck injury during the final game of the 1994 regular season. His neck snapped back while blocking during a running play, which nearly left him paralyzed. He never again returned to the football field following the injury.

#1 - Terrell Davis

Denver Broncos RB Terrell Davis

During a three-year stretch between the 1996 and 1998 NFL seasons, Terrell Davis was one of the best players in the league. It was also one of the best three-year runs by any running back ever. He exceeded 1,500 rushing yards in each year. He won an NFL MVP award and two Offensive Player of the Year awards while being chosen as a first-team All-Pro in all three seasons.

The final year of that stretch was Davis' best, when he exceeded 2,000 rushing yards. He became one of only eight players ever to do so. The following season, when trying to make a tackle after an interception, he tore his ACL and MCL. He would never fully recover and retired early just two years later after recording just two touchdowns in 13 games over the next two seasons.