Major League Baseball announced its new guidelines for substance enforcement on Tuesday, including a 10-day suspension for any pitcher who "possesses or applies foreign substances" during a game.
MLB distributed a memo to teams detailing its new policy on Tuesday. Widely-used substances such as sunscreen will now be banned, as will Spider Tack, a now-popular grip substance. Enforcement of the new policy will begin on Monday, June 21.
The use of different substances to affect a baseball's movement is a decades-long practice, though it has come under greater scrutiny in recent months. More advanced grip enhancers such as Spider Tack have led to a spike in spin rate on various pitches, helping contribute to the league-wide offense shortage.
Numerous notable pitchers have been involved in MLB's pitch-doctoring scandal, including Yankees ace Gerrit Cole, Cardinals veteran Adam Wainwright and 2020 Cy Young winner Trevor Bauer. Wainwright responded to a Sports Illustrated report on pitch doctoring on Monday night, noting the substances he used "didn't work for me."
Players across the league have begun to brace for the impending ban on Spider Tack and similar substances, per ESPN's Jeff Passan. Some pitchers have begun to throw bullpen sessions without any foreign substances, while those who used Spider Tack have transitioned to using only pine tar.
Umpires will be expected to check for foreign substances between innings. Cardinals pitcher Giovanny Gallegos was forced to remove his hat due to a substance in May, which led to the ejection of St. Louis manager Mike Shildt.