The NFL has sent a memo to team personnel of all 32 teams reminding them about the league's position in regards to faking injuries to gain a play stoppage without using a timeout.

The NFL has been reluctant to propose a specific rule because of the value of timeouts within the game and because it could encourage injured players to stay in the game.

"To avoid the necessity of a rule with many unattractive qualities, teams are strongly urged to cooperate with this policy," the memo states. "We are determined to take all necessary steps to ensure that it does not become an issue. We have been fortunate that teams and players have consistently complied with the spirit of the rule over the years and this has not been an issue for the NFL. We are determined to take all necessary steps to ensure that it does not become an issue."