Baseball · All Baseball players
Riley O'Brien
MLB
About Riley O'Brien
Riley Chun-Young O'Brien (born February 6, 1995) is an American professional baseball pitcher for the St. Louis Cardinals of Major League Baseball (MLB). He has previously played in MLB for the Cincinnati Reds and Seattle Mariners. O'Brien played college baseball and Everett Community College and the College of Idaho. He was selected by the Tampa Bay Rays in the eight round of the 2017 Major League Baseball draft and made his MLB debut in 2021 with the Reds. With St. Louis, O'Brien was named to his first All-Star game in 2026 and was tied with Mason Miller for the NL lead in saves that same year with 38.
Bio summary from Wikipedia.
Player Stats
| G | 2 | PA | 0 | AB | 0 | R | 0 |
|---|---|---|---|---|---|---|---|
| H | 0 | 2B | 0 | 3B | 0 | HR | 0 |
| RBI | 0 | SB | 0 | CS | 0 | BB | 0 |
| SO | 0 | TB | 0 | WAR | 0.0 |
2026 batting — Baseball-Reference
Player Stats
| W | 3 | L | 9 | ERA | 4.08 | G | 66 |
|---|---|---|---|---|---|---|---|
| GS | 0 | SV | 38 | IP | 64.0 | H | 53 |
| R | 35 | ER | 29 | BB | 29 | SO | 64 |
| WHIP | 1.281 | H/9 | 7.5 | HR/9 | 0.7 | BB/9 | 4.1 |
| K/9 | 9.0 | FIP | 3.94 | WAR | 0.0 |
2026 pitching — Baseball-Reference
Career — Lahman, through 2025
Pitching
| Year | Team | W | L | ERA | G | GS | CG | SHO | SV | IP | H | HR | BB | SO |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2021 | CIN | 0 | 1 | 13.50 | 1 | 1 | 0 | 0 | 0 | 1.1 | 2 | 2 | 3 | 2 |
| 2022 | SEA | 0 | 0 | 0.00 | 1 | 0 | 0 | 0 | 0 | 1.0 | 1 | 0 | 1 | 1 |
| 2024 | SLN | 0 | 0 | 11.25 | 8 | 0 | 0 | 0 | 0 | 8.0 | 13 | 2 | 8 | 11 |
| 2025 | SLN | 3 | 1 | 2.06 | 42 | 0 | 0 | 0 | 6 | 48.0 | 33 | 2 | 22 | 45 |
Season lines from the Lahman Baseball Database (Version 2025, via SABR), joined through the Chadwick Register ID crosswalk. The databank runs through the 2025 season — the current season is the 2026 line below, from the MLB Stats API.
2026 Season — MLB Stats API
Batting
| G | PA | AB | R | H | 2B | 3B | HR | RBI | SB | CS | BB | SO | AVG | OBP | SLG | OPS |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 66 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | — | — | — | — |
Pitching
| W | L | ERA | G | GS | CG | SHO | SV | IP | H | R | ER | HR | BB | SO | WHIP |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 3 | 9 | 4.08 | 66 | 0 | 0 | 0 | 38 | 64.0 | 53 | 35 | 29 | 5 | 29 | 64 | 1.28 |
2026 regular-season line from the MLB Stats API (statsapi.mlb.com), pulled when this page was built. Multi-team stints are combined; rate stats are recomputed from the combined totals.
Watch Riley O'Brien Highlights
“Riley O'Brien 2026 MLB Highlights!” · Open on YouTube · More Riley O'Brien videos