Non-MLB
Although they have not thrown an MLB pitch in 2025, Roman Mendez threw 1,332 pitches that were tracked by the PITCHf/x system between 2012 and 2024, including pitches thrown in the MLB Regular Season, Spring Training and Fall/Winter Ball. In 2024, they relied primarily on their Fourseam Fastball (92mph), Slider (83mph) and Splitter (85mph). He also rarely threw a Sinker (91mph).
In 2024, compared to other RHP:
Their fourseam fastball is a real worm killer that generates an extreme number of groundballs compared to other pitchers' fourseamers, has some natural sinking action, has essentially average velo and has slight armside run. Their slider has less than expected depth. Their splitter is a real worm killer that generates an extreme number of groundballs compared to other pitchers' splitters. Their sinker (take this with a grain of salt because they've only thrown 9 of them in 2024) is basically never swung at and missed compared to other pitchers' sinkers, results in more flyballs compared to other pitchers' sinkers and has less armside run than typical.