When linebacker Clint Sellers was laying on the field motionless on the opening kickoff of Saturday’s game at Illinois, players and coaches were worried about whether he would be able to walk, much less play football again.

Fortunately, Sellers (above) was able to walk off the field with the trainers’ assistance.

But not everybody has been that lucky.

Here are three players’ professional careers that were ended prematurely:

1. Joe Theismann – When Lawrence Taylor and Gary Reasons sacked Theismann in a Nov. 18, 1985, game, Taylor landed on Theismann’s leg, destroying his tibia and fibula. It was a break that eventually ended his career.

2. Dave Dravecky – In the sixth inning of a game against the Montreal Expos in 1989, Dravecky, then pitching for the San Francisco Giants, wound up, was about to throw the ball and then snapped his upper arm bone. With the ball in the stands, Dravecky’s left arm dangled at his side. Cancer that he thought he had beaten had returned and forced him into retirement.

3. Mike Utley – The Detroit Lions played the Los Angeles Rams on Nov. 17, 1991 in Utley’s last football game. The Lions offensive lineman stepped back to pass block when a pass rusher jumped up to swat a pass. He landed on Utley and fractured the sixth and seventh cervical vertebrae, leaving Utley paralyzed. His thumbs-up sign, given while leaving the field on a stretcher, has been duplicated several times since then.