Jan Ziolkowski
Jan Ziolkowski, 21, from Poland ➤ AC Monza, since 2026 ➤ Centre-Back ➤ Market value: €12.00m ➤ * 05/06/2005 in Warszawa, Poland

Info
Biographical card, current club and contract facts. Empty fields mean the source did not publish that value.
Statistics
Career totals from Transfermarkt: this season, then by competition and by club. Minutes and cards appear when the source recorded them.
This season
| Season | Competition | Apps | Min | G | A | YC | RC |
|---|---|---|---|---|---|---|---|
| 26/27 | Italy Cup | 1 | 14 | 0 | 0 | 0 | 0 |
| 26/27 | Serie A | 0 | 0 | 0 | 0 | 0 | 0 |
By competition
| Competition | Apps | G | A |
|---|---|---|---|
| Betclic 3 Liga - Group I | 38 | 2 | 2 |
| Ekstraklasa | 24 | 1 | 2 |
| Serie A | 18 | 0 | 0 |
| Youth League POL | 11 | 0 | 1 |
| STS Polish Cup | 6 | 1 | 0 |
| Conference League | 5 | 0 | 0 |
| Europa League | 4 | 1 | 0 |
| Europa League Qualifying | 4 | 0 | 0 |
| UECL Qualifying | 3 | 0 | 1 |
| Italy Cup | 2 | 0 | 0 |
| Superpuchar | 1 | 0 | 0 |
By club
| Club | Apps | G | A |
|---|---|---|---|
| Legia II | 41 | 2 | 2 |
| Legia Warszawa | 40 | 2 | 3 |
| Roma | 23 | 1 | 0 |
| Legia U19 | 11 | 0 | 1 |
| Monza | 1 | 0 | 0 |
Transfers
Recorded moves between clubs, with fee and market value on the day of the deal when the source has them.
| Date | Season | From | To | Fee | Market value |
|---|---|---|---|---|---|
| 30/06/2027 | 26/27 | Monza | Roma | End of loan | €12.00m |
| 31/08/2026 | 26/27 | Roma | Monza | Loan fee:<br /><i class="normaler-text">€500k</i> | €12.00m |
| 29/08/2025 | 25/26 | Legia Warszawa | Roma | €6.60m | €4.00m |
| 25/01/2023 | 22/23 | Legia II | Legia Warszawa | - | - |
| 01/08/2022 | 22/23 | Legia U19 | Legia II | - | - |
| 01/07/2022 | 22/23 | MKS Polonia U19 | Legia U19 | ? | - |
National
Senior and youth national-team spells: caps, goals, shirt number and whether the player is still in the current pool.
| Team | Caps | Goals | Shirt | Debut | Status |
|---|---|---|---|---|---|
| Poland | 3 | 0 | 16 | 2025-10-09 | recent national player |
| Poland U18 | 2 | 0 | 4 | 2023-03-24 | Former international |
| Poland U19 | 3 | 0 | 18 | 2023-09-07 | Former international |
| Poland U20 | 5 | 1 | 19 | 2024-09-09 | Former international |
Market value
Current and peak Transfermarkt valuations, plus the history of changes by club and age. Rankings are relative to the current squad, league and position group.
- Current
- €12.00m
- Highest
- €12.00m · 24/03/2026
- Last change
- 29/05/2026
| Date | Age | Club | Value |
|---|---|---|---|
| 09/06/2023 | 18 | Legia Warszawa | €250k |
| 29/12/2023 | 18 | Legia Warszawa | €450k |
| 07/06/2024 | 19 | Legia Warszawa | €800k |
| 20/09/2024 | 19 | Legia Warszawa | €1.50m |
| 09/12/2024 | 19 | Legia Warszawa | €1.20m |
| 03/04/2025 | 19 | Legia Warszawa | €2.50m |
| 06/06/2025 | 20 | Legia Warszawa | €4.00m |
| 07/10/2025 | 20 | AS Roma | €6.00m |
| 23/12/2025 | 20 | AS Roma | €7.50m |
| 24/03/2026 | 20 | AS Roma | €12.00m |
| 29/05/2026 | 20 | AS Roma | €12.00m |
xG Statistics
Jan Ziolkowski's xG Statistics block is an Understat shot model for the 2025 season. It does not replace goals and assists — it explains them. xG and xA ask whether the chances were good enough; xGChain and xGBuildup show how often the player was on the ball in moves that became shots. Use minutes as the denominator: a large xG in 80 minutes is a hot streak, the same xG over 1,200 minutes is a role. Figures are rounded to two decimals and stay empty when Understat has no match for this player.
| Season | League | Club | Apps | Min | G | xG | npxG | A | xA | Sh | KP | xGChain |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2025 | Serie A | Roma | 18 | 500 | 0 | 0.14 | 0.14 | 0 | 0.04 | 2 | 1 | 0.8 |
What the columns mean
Read this table as chance quality, not as a scoreboard. A player can outscore xG (finishing well) or lag behind it (missed sitters). Compare rows only when minutes are in the same range.
Apps· Appearances- Matches in which the player was used in this league season, including substitute minutes.
Min· Minutes- Total minutes on the pitch. Useful when comparing output: 1 goal in 90 minutes is not the same as 1 goal in 800.
G· Goals- Goals credited to the player in the Understat shot model for that season.
xG· Expected goals- The quality of shots the player took, expressed as the number of goals an average finisher would score from the same chances. A 0.30 xG shot is a chance that goes in about 3 times in 10.
npxG· Non-penalty xG- Expected goals with penalties removed. This is the cleaner read of open-play and set-piece finishing, because a penalty is usually ~0.76 xG by itself.
A· Assists- Goals that followed the player's last pass. Actual assists, not the model.
xA· Expected assists- The xG value of shots that came directly from the player's key passes. High xA with few assists usually means teammates missed good chances.
Sh· Shots- Total shots recorded by Understat, including blocked and off-target attempts.
KP· Key passes- Passes that led to a shot. This is the volume behind xA.
xGChain· xG chain- Team xG from possessions the player touched. It captures involvement in build-up, not only the shot or the last pass. A midfielder who starts attacks can rank high here without scoring.
xGBuildup· xG buildup- The same possession xG, but excluding the shot-taker and the assist. This is the purest 'how much did this player help create the chance before the final ball' number.
NPG· Non-penalty goals- Goals scored from open play or set pieces, excluding penalties.







