Seattle Mariners
Although they have not thrown an MLB pitch in 2026, Leo Rivas threw 38 pitches that were tracked by the PITCHf/x system between 2024 and 2025, all of them occuring in the MLB Regular Season. In 2025, they relied primarily on their Fourseam Fastball (43mph).
In 2025, compared to other RHP:
Their fourseam fastball (take this with a grain of salt because they've only thrown 18 of them in 2025) comes in below hitting speed, has heavy sinking action, is basically never swung at and missed compared to other pitchers' fourseamers, is straight as an arrow and results in somewhat more groundballs compared to other pitchers' fourseamers.