Scouting Report: Trey Riley
Chicago Cubs | RP
Overall
Summary
Riley O'Brien is a 31-year-old relief pitcher for the St. Louis Cardinals who has emerged as a breakout star in 2026. Originally drafted by Tampa Bay in 2017, O'Brien has had a long developmental path through multiple organizations (Rays, Reds, Mariners) before joining the Cardinals in November 2023. After showing improved strikeout rates and walk rates at AAA Tacoma in 2023, O'Brien has translated that success to MLB. Through early May 2026, he has become one of the most productive relievers in baseball and a stabilizing force for the Cardinals' bullpen. His primary weapon is a 98.3 mph sinker with above-average drop and ride, complemented by an effective sweeper and slider. His Statcast metrics show elite performance across Chase%, Whiff%, K%, and BB% categories, indicating tangible improvement rather than small-sample luck.
Strengths
- Elite strikeout rate with improved K%-BB% ratio
- Exceptional sinker velocity (98.3 mph average) with plus movement
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