For sports organizations and leagues, the stakes are high. For more than a decade, access to social media has given sports stars the ability to become more outspoken and impactful than ever. As long as what they say has not been offensive or polarizing, they provided free, mostly positive publicity for their sports, their causes and their own brands.

The vaccination issue has changed the equation for sports, whose return in 2020 was viewed positively when they modeled safe behavior, such as mask wearing, playing before sparse crowds or no one at all, and participating in regular testing. The behavior and outspokenness of Djokovic, Rodgers, Irving and others against vaccines has jeopardized that good will, and organizations are now tightening their rules to play defense.