#3 Shawn Michaels made a return to WWE following his first retirement due to injury
Shawn Michaels was one of WWE's biggest stars throughout the 90's. Sadly, at the Royal Rumble pay-per-view in 1998, HBK sustained a career-ending injury. In a Casket Match with The Undertaker, Michaels' received a back body drop onto the casket.
His lower back collided with the casket and herniated two disks, completely shattering one of them. It was a devastating moment for the then-WWE Champion.
It was a difficult time for WWE and Shawn Michaels, as WWE was at the peak of the Attitude Era competing against WCW. Michaels would eventually get surgery on his back. He quietly retired from in-ring competition and returned on-screen as a commissioner.
In 2002, some four years after first sustaining his injuries, Shawn Michaels signed a new contract with WWE, which was a performers contract. Michaels made his return to action feuding with long-time friend Triple H. It was a massive coup for WWE, as HBK is considered to be one of the greatest ever performers to step into the ring.