Teams competing in Major League Baseball (MLB) this season must notify the Commissioner’s office of their starting line-ups before being announced at stadiums.
The league believes the growth of sports betting will lead to information being breached and shared illegally.
An MLB decision made on Thursday requires teams to send their game-day squad to the league’s data operations group at least 15 minutes ahead of any public announcement.
A statement from the Commissioner’s office said: "We are updating a number of procedures to reduce integrity risks associated with the expansion of sports betting in light of the Supreme Court’s ruling last may.
"One new procedure is we now ask clubs to submit starting line-ups in a uniform fashion to reduce the risk of confidential information being tipped."
MLB says this decision mirrors those of international sports leagues in more developed betting markets.
In previous seasons, teams have announced line-ups as and when they wanted, some through social media, others in stadiums.