Following his move to Telstar, Mertens's current-season form is down 33% on last season (Season 9→6), while his Rating climbed 19→23. His peak season for form remains 2024/25 (Season 9).

Domestic career

Season	Club	Apps	G	A	Match	RTG	Season
2025/26	Telstar · 14th	20	0	0	6.57	23	6
2024/25	Fakel · 16th	27	0	0	6.47	19	9
2023/24	Botev Plovdiv	11	3	1	6.73	—	—
2022/23	Botev Plovdiv	26	1	0	—	—	—
2021/22	Botev Plovdiv	30	0	0	—	—	—

Domestic-league totals per season. RTG = Field Insider Rating (potential / ceiling); Season = age-blind form that year. 5 earlier seasons in the full career.

Scout report

Experienced headBall-winning Defensive midfielder

D. Mertens is a 31-year-old defensive midfielder at Telstar, rated 23.2 overall by Field Insider's model. A seasoned veteran, he has been a fringe squad member this season (16.9% of available minutes). His defensive output reads 5 tackles, blocks and interceptions per 90. Below: strengths, watch-points, market-value outlook and the latest transfer news on Mertens.

On the season, Mertens graded 6 for current form (age-blind), on 0 goals, 0 assists and 5 defensive actions per 90.

Year-on-year, that's broadly in line with last season (Season 9 → 6).

On long-term talent our Rating reads 23. At 31 Mertens is into the veteran stage, where the age curve weighs on the projection, and a market index of 4.8 reflects that trajectory.

From the career report

Read the full career report →

Below his 2024/25 peak but holding a solid level — the platform for a return is there.

Peak: 2024/25Holding level

23.2

Ratingi

below regular-starter level

6.4

Seasoni

below regular-starter level

16.9%

Minutes

limited game time

Def. actions / 90

high defensive volume

Output in context · Telstar finished 14th of 18 · a lower-table side

Def. / 90

Tackles

Interceptions

Clean sheets

5 tackles, blocks & interceptions per 90 — high defensive volume, with 1 clean sheet across 20 appearances. Doing that for a lower-table side (14th of 18) is harder than the bare numbers suggest: a back line under more pressure has to defend more often and protects fewer leads, so the volume — and any clean sheets — carry real weight.

Strengths

Defensive volume. 5 tackles, blocks & interceptions per 90 — does the unseen work.

Watch points

Game time. Only 16.9% of available minutes — needs a settled run to prove the level.
Age curve. At 31, both level and resale value are on the downslope.
Level. Rates below a nailed-on top-tier starter on our model.

Outlook

Rated 23.2 overall — below regular-starter level. Defensively he reads as high defensive volume (5 tackles, blocks & interceptions per 90). Veteran phase — a short-term, lower-fee proposition as both level and value decline (0.9× and falling).

Generated from Field Insider's rating model · AI-written analysis to follow.

Per 90 & availability

Minutes played %16.9%

Available fixtures32 of 34

Goals / 900

Assists / 900

Goal contribution / 900

Defensive actions / 905

Player flow

Goal involvements0

Shot conversion %0

Shot accuracy %33.3

Pass accuracy %79

Dribble success %60

Cards / 900.37

Foul involvement / 903.704

Season-by-season progression

Rating (potential)Season (form)

Value & potential by age

Market valueRating

Solid = now · dashed = projected

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 (~11), then tapers with age. At 31, Mertens sits on 4.8, past its peak and easing. The blue line is Mertens's projected Rating — 23.2 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.