Non-MLB
Although they have not thrown an MLB pitch in 2024, J.C. Romero threw 3,229 pitches that were tracked by the PITCHf/x system between 2007 and 2012, including pitches thrown in the MLB Regular Season, the MLB Postseason and Spring Training. In 2012, they relied primarily on their Sinker (90mph), also mixing in a Change (80mph), Slider (81mph) and Fourseam Fastball (91mph).
In 2012, compared to other LHP:
Their sinker has slight armside run and has some natural sinking action. Their change is an extreme flyball pitch compared to other pitchers' changeups, has slightly below average velo and has some natural sink to it. Their slider has primarily 12-6 movement and has some two-plane movement. Their fourseam fastball has heavy sinking action, is basically never swung at and missed compared to other pitchers' fourseamers, has essentially average velo, results in somewhat more flyballs compared to other pitchers' fourseamers and has slight armside run.