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 · played P 66 · MLB debut 2021-09-28
281 batters faced scored this season His season card →
Scout’s note
Riley O'Brien is 31, an eighth-round pick out of Seattle who debuted in 2021, and this year he's fourth in the National League with 38 saves for St. Louis. The board holds him ungraded — our stuff model isn't outcome-validated, so no big-league arm earns a flag from it. But the ERA-FIP luck gap on his 4.08 ERA over 64 innings did trip the regression threshold, and we file those calls by hand. A 0.3-WAR reliever with 38 saves is the kind of line that makes you check the physics twice.
Note written · FVR scout (GLM-5.2)
Current signals
The read: O'Brien is in the Index ungraded, on purpose: our stuff model is stability-tested but not outcome-validated, so no big-league arm gets a board flag from it — not even one of the best seasons in the sport. (Calls are another matter: the ERA-FIP luck gap did clear the bar, and we file arm regression calls by hand from it.) The page is here because the player matters; the board grade waits for the science.
What he’s paid
Pre-arbitrationA market fact, not an engine read: what a club decided about him, on the season before this one. Figures from Cot’s, as of .
- 2026 salary
- —est
- Service time
- 2 yr 129 d
- Options left
- 0 / 3
After this season, as the sheet has it
| Season | 2028 | 2029 | 2030 | 2031 |
|---|---|---|---|---|
| Cash | Arb 1 | Arb 2 | Arb 3 | Free agent |
| Tax hit | — | — | — | — |
Cash and the tax hit are two different rulebooks and are never subtracted from one another — see the payroll board for his club, St. Louis Cardinals.
A second set of books
The same contract, read by MLB Spreadsheets (Ethan Hullihen), as of . We keep two sources on this because one source cannot check itself.
- Tax AAV
- $0.80M
- Guaranteed
- $0.80M
- Term
- 1 yr
- His class
- Pre-Arb
What the sheet prices each season at
| Season | 2026 | 2027 | 2028 | 2029 | 2030 |
|---|---|---|---|---|---|
| Salary | Minimum | Minimum | Arb 1 | Arb 2 | Arb 3 |
A base salary under his own reading, and never subtracted from the cash figure above: a signing bonus lands in one and not the other, so the two disagree on most men without either being wrong. And the sheet does not mark which future seasons are GUARANTEED — a club option and a projected arbitration award are both just a number here, so read past the end of the deal as his forecast rather than as money owed.
Two sources, read a month apart, put this guarantee at the same dollar. That is the check, and it passed.
The tax AAV above is his number under the CBA’s own rulebook, not the average we work out from Cot’s total. On a contract with deferred money the two come apart on purpose — and neither is subtracted from the other.
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 Bureau on Riley O'Brien
The scouting press, in their own words
Riley O'Brien in Coors? Buckle up.
Umpire favor
+0.4 net runs over 25 graded games — the zone was kind to the umpire on balance.
The line
| 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 | 66 | 64.0 | 3–9 | 38 | 4.08 | 64 | 1.28 |
| MLB CAREER | 118 | 122.1 | 6–11 | 44 | 3.83 | 123 | 1.35 | ||
Bio & season lines: MLB StatsAPI · refreshed nightly · abbreviations →