| Season | Team | Competition | MP | G | A | Rating | ||
|---|---|---|---|---|---|---|---|---|
| 2025 | KTP | League Cup | 2 | 0 | 0 | 0 | 0 | – |
| 2025 | KTP | Suomen Cup | 0 | 0 | 0 | 0 | 0 | – |
| 2024 | Gnistan | League Cup | 4 | 0 | 0 | 0 | 0 | – |
| 2024 | Gnistan | Suomen Cup | 1 | 0 | 0 | 0 | 0 | – |
| 2021 | Gnistan | Suomen Cup | 5 | 0 | 0 | 0 | 0 | – |
| 2019 | KTP | Suomen Cup | 4 | 0 | 0 | 0 | 0 | – |
| 2017/2018 | KTP | Suomen Cup | 2 | 0 | 0 | 0 | 0 | – |
| 2016/2017 | KTP | Suomen Cup | 5 | 0 | 0 | 0 | 0 | – |
| 2016 | HJK | Suomen Cup | 0 | 0 | 0 | 0 | 0 | – |
| 2013/2014 | Vejle | DBU Pokalen | 0 | 0 | 0 | 0 | 0 | – |
| 2012 | JJK | League Cup | 0 | 0 | 0 | 0 | 0 | – |
| Total | 23 | 0 | 0 | 0 | 0 | – | ||
| Date | From | To | Type | |
|---|---|---|---|---|
| - | Vejle | Atlantis Helsinki | Transfer | |
| 01 Jan 2016 | Atlantis Helsinki | Klubi-04 | Transfer | |
| 01 Jan 2016 | Atlantis Helsinki | HJK | Transfer | |
| 01 Jan 2017 | HJK | KTP | Transfer | |
| 01 Jan 2020 | KTP | EIF | Transfer | |
| - | EIF | Gnistan | Transfer | |
| 01 Jan 2025 | Gnistan | KTP | Transfer |
J. Koski career history shows progression across clubs and competitions, including club timeline, national team appearances and overall career totals.