Which of the following is NOT a reason for the forfeiture of a player's contract?

The rationale behind selecting injury due to a game as the answer lies in understanding the nature of player contracts and the specific provisions that govern them. In professional football, contracts typically include clauses that address various scenarios that might lead to the forfeiture of a player's contract.

Injuries sustained during the course of a game are generally considered part of the inherent risks of playing professional sports. Therefore, such injuries are often covered by the terms of the contract rather than resulting in forfeiture. This allows players to remain protected under their contracts even when they face injuries that occur during official play.

On the other hand, retirement, jail time, and non-football injuries can lead to contract forfeiture depending on the circumstances and specific terms outlined in the player's contract. Retirement is seen as an end to a player's career with the team, jail time often results in a breach of conduct, and non-football injuries may not fall under the protections provided for players during their employment. Thus, the correct answer highlights the unique treatment of injuries sustained during a game within the context of a player's contract.