He has a severely damaged neck which puts him at risk for long-term health. Why is he contemplating playing more seasons instead of simply retiring?
An ideal scenario for leaving sports has been painted. A professional athlete plays for one team in his career and walks away from the sport on his own terms. He gracefully retires with his health and welfare intact. In reality this idealized scenario virtually never occurs.
In 40 years of athletic representation I have rarely seen an athlete voluntarily retire from his career. They may be injured to the point that teams don't want to risk employing them. Their talent may have degraded to the level that finds no employer. Or their conduct and rules violations may have excluded them from competition. They almost never leave sports willingly.
Most pro athletes have been playing sports since early childhood. Their whole life has been structured around practicing and playing in games. It is all they have ever experienced. The concept of leaving the familiar to embark in a new career is daunting.
Pro athletes are the most competitive humans on the face of the planet. They would put intensity into beating you at Tiddlywinks. I learned early on to never compete athletically with clients. I happened to be a fairly talented ping-pong player. In the first visit to Atlanta following his signing, my first client Steve Bartkowski challenged me to a game of ping pong. With little understanding of athletic mentality I played my hardest and beat him. He refused to speak with me for the rest of the day and I feared he would be my last client. Athletes love the challenge of competition and don't want to give it up.