Biggest pro football accomplishments: Made five Pro Bowls and was selected to the All-Pro team three times during a 14-year career that saw him play linebacker for the Rams, Steelers, Panthers, and 49ers
Biggest pro wrestling accomplishments: Wrestled alongside fellow NFL player Steve "Mongo" McMichael in WCW before later teaming up with former NFL player Bill Goldberg to wrestle against WCW's nWo faction
The key to his career change: He was willing to take part in WCW matches while he was still playing in the NFL.

Greene is one of the only NFL players to ever wrestle on a semi-regular basis while he was still playing football. Teams eventually forced him to stop wrestling by adding a "no wrestling" clause to his contracts. But for awhile there, Greene was using his NFL popularity to aid his wrestling career and vice versa. Had he taken wrestling a little bit more seriously or retired from the NFL altogether to wrestle, he likely would have played a much bigger role in WCW.