Domestic-league season · K. Lierse S.K..
| Competition | Apps | G | A | Min | Match |
|---|---|---|---|---|---|
 Challenger Pro League | 23 | 4 | 4 | 1476 | 7.38 |
Following his move to K. Lierse S.K., Mertens's current-season form is up 87% on last season (Season 15→28), while his Rating held around 40. That makes this his strongest season for form to date.
| Season | Club | Apps | G | A | Match | RTG | Season |
|---|---|---|---|---|---|---|---|
| 2025/26 | K. Lierse S.K. · 10th | 23 | 4 | 4 | 7.38 | 40 | 28 |
| 2023/24 | SK Beveren · 8th | 13 | 1 | 2 | 6.9 | 41 | 15 |
| 2022/23 | SK Beveren · 2nd | 5 | 0 | 0 | — | 39 | 3 |
| 2021/22 | SK Beveren · 3rd | 19 | 1 | 0 | — | 45 | 8 |
| 2020/21 | SK Beveren · 17th | 14 | 0 | 0 | 6.8 | 47 | 2 |
Domestic-league totals per season. RTG = Field Insider Rating (potential / ceiling); Season = age-blind form that year.
J. Mertens is a 26-year-old full-back at K. Lierse S.K., rated 40.1 overall by Field Insider's model, ranking 122nd of 235 in the Challenger Pro League. In his prime years, he has been a rotation option this season (51.2% of available minutes). His defensive output reads 4.7 tackles, blocks and interceptions per 90. Below: strengths, watch-points, market-value outlook and the latest transfer news on Mertens.
Judged on this season alone, Mertens graded 28 — a strong campaign that ranks top 16% of the 33 full-backs in the Challenger Pro League, on 5 clean sheets and 4.695 defensive actions per 90.
Year-on-year, that's a clear step up on last season (Season 15 → 28). Across the 5 seasons we hold, it's his best return yet.
On long-term talent our Rating reads 40, 18th of 33 of the 33 full-backs in the Challenger Pro League. At 26 Mertens is in his prime years, and a market index of 9.3 reflects that trajectory.
A career still climbing — Mertens is at his peak right now, and the curve hasn't flattened.
4.7 tackles, blocks & interceptions per 90 — solid defensive volume, with 5 clean sheets across 23 appearances. Going forward he chipped in 4 goals and 4 assists — a useful bonus from the back.
With a Rating of 40.1, Mertens carries the 18th-highest potential of the full-backs in the Challenger Pro League of 33. Defensively he reads as solid defensive volume (4.7 tackles, blocks & interceptions per 90), with a bit more on the ball than most in the role. In the prime window — at or near peak market value, so the next two seasons are the ones to cash in or build around.
Generated from Field Insider's rating model · AI-written analysis to follow.
The gold line is market value — an index (not €) blending rating, age and league. It climbs through the early 20s, peaks around ages 23–27 (~9), then tapers with age. At 26, Mertens sits on 9.3, at or near its peak. The blue line is Mertens's projected Rating — 40.1 today — recomputed at each age, so it follows the same rise-and-fall as a career matures and declines. Solid = up to today; dashed = projected.
No transfer news found for this player.
