MLB · P · St. Louis Cardinals
Riley O'Brien
B/T R/R · 6' 4" · 180 lb · born Seattle, WA, USA · age 31 · draft 2017 rd 8 · MLB debut 2021-09-28
Scout’s note
O'Brien, a 2017 eighth-round pick out of Seattle, WA, owns a career 3.50 ERA with 98 strikeouts over 97.2 big-league innings and 30 saves. An Index name: one of the game's biggest seasons, watched nightly. No call, because the engine found nothing mispriced to call.
Current signals
The read: O'Brien is in the Index ungraded, on purpose: our pitching signals are stability-tested but not outcome-validated, so no big-league arm gets a board flag or a call — not even one of the best seasons in the sport. The page is here because the player matters; the grade waits for the science.
Collect Riley O'Brien
If the signal is right, the cardboard usually finds out later. Current listings:
Riley O'Brien cards on eBay →Paid link — as an eBay Partner, FVR earns from qualifying purchases.
Not financial advice. We take positions only after publication — never before. Misses stay on the record.
The line
Last 14 days (through 2026-07-15): 4 G · 4.0 IP · 0.00 ERA · 5 SO · 0.75 WHIP
| Year | Team | Lvl | G | IP | W–L | SV | ERA | SO | WHIP |
|---|---|---|---|---|---|---|---|---|---|
| 2021 | Cincinnati Reds | MLB | 1 | 1.1 | 0–1 | 0 | 13.50 | 2 | 3.75 |
| 2022 | Seattle Mariners | MLB | 1 | 1.0 | 0–0 | 0 | 0.00 | 1 | 2.00 |
| 2024 | St. Louis Cardinals | MLB | 8 | 8.0 | 0–0 | 0 | 11.25 | 11 | 2.63 |
| 2025 | St. Louis Cardinals | MLB | 42 | 48.0 | 3–1 | 6 | 2.06 | 45 | 1.15 |
| 2026 | St. Louis Cardinals | MLB | 39 | 39.1 | 3–3 | 24 | 3.43 | 39 | 1.12 |
| MLB CAREER | 91 | 97.2 | 6–5 | 30 | 3.50 | 98 | 1.30 | ||
Bio & season lines: MLB StatsAPI · refreshed nightly · abbreviations →