Last with Kansas City Royals · P · No longer on a 40-man roster
Jackson Kowar has an estimated 2 years and 102 days of major league service time — 2.102 in the notation clubs use, from 446 days credited on a major league roster.
| Season | Club | Days | Running total | How this season is known |
|---|---|---|---|---|
| 2021 | Kansas City Royals | 49 | 0.049 | From transactions |
| 2022 | Kansas City Royals | 37 | 0.086 | From transactions |
| 2023 | Kansas City Royals | 74 | 0.160 | From transactions |
| 2024 | Seattle Mariners | 172 | 1.160 | From transactions |
| 2025 | Seattle Mariners | 114 | 2.102 | From transactions |
| 2026 | Seattle Mariners, Minnesota Twins, Baltimore Orioles | 0 | 2.102 | From transactions |
172 days credit a full year, so a season adds at most 1.000 no matter how long a player is on a roster. 3.000 years reaches salary arbitration and 6.000 reaches free agency —
what every threshold unlocks.
This figure is an estimate reconstructed from public roster
transaction records. It is not an official MLB or MLBPA figure — those are
not published. See the
methodology.
Last updated 2026-10-12.
Independent project, not affiliated with or endorsed by Major League
Baseball or the MLBPA.