The app, called Rally, gives fans the opportunity to win cash prizes by predicting outcomes of at-bats and games.
Fans collect points by selecting the correct outcome.
Top points earners will share a daily prize pool. Prize pools can reach at least $5,000.
Chris Marinak, MLB executive vice president of strategy, technology, and innovation, said: “There’s no sports betting element in any of our apps. It is important we stick to gaming.”
The MLB season begins Thursday with two Opening Day matchups.