The NFL scouting combine has sent a memo to all prospective players attending next month's annual pre-draft event in Indianapolis, revising its policies and procedures regarding COVID-19 protocols.

The memo came hours after the potential of player boycotts made news. According to sources, a group of player agents was threatening to organize a boycott of certain key elements of the combine if its concerns about a COVID-19 "bubble" continued to be ignored.

The memo, obtained by ESPN, focuses on mask-wearing for both the players and medical personnel, as well as defining the event's secure areas, keys points of contention among players' agents.