Gu Sung-Yun

Following his move to FC Seoul, Sung-Yun's current-season form is up 675% on last season (Season 4→31), while his Rating climbed 15→19. That makes this his strongest season for form to date.

Domestic career

Season	Club	Apps	CS	CS%	Match	RTG	Season
2026/27	FC Seoul · 1st	25	5	20%	6.77	20	22
2025/26	FC Seoul	4	0	0%	6.58	—	—
2025/26	Kyoto Sanga · 3rd	2	1	50%	6.55	15	4
2024/25	Kyoto Sanga · 14th	32	9	28%	6.73	31	23
2023/24	Kyoto SangaLoan · 13th	16	3	19%	6.24	30	6
2023/24	Consadole Sapporo	3	0	0%	—	—	—
2022/23	Gimcheon Sangmu FC · 3rd	15	3	20%	7.16	32	5

Domestic-league totals per season. RTG = Field Insider Rating (potential / ceiling); Season = age-blind form that year. 7 earlier seasons in the full career.

Korea Republic · international

Side	Apps	G
Korea Republic U23	4	0
South Korea	4	0

Career caps & goals — tournament breakdown in the full career.

Scout report

Experienced headGoalkeeper

Gu Sung-Yun is a 32-year-old goalkeeper at FC Seoul, enjoying a standout season — 0 goals and 0 assists in 25 appearances, a Season grade of 31, top 23% of K League 1 goalkeepers. On long-term scout potential he's rated 19.1, ranking 68th of 83 in the K League 1. A seasoned veteran, he has been a rotation option (40% of available minutes). Below: strengths, watch-points, market-value outlook and the latest transfer news on Sung-Yun.

Judged on this season alone, Sung-Yun graded 31 — a strong campaign that ranks top 24% of the 13 goalkeepers in the K League 1, on 5 clean sheets across 25 appearances.

Year-on-year, that's a clear step up on last season (Season 4 → 31). Across the 6 seasons we hold, it's his best return yet.

On long-term talent our Rating reads 19, 8th of 13 of the 13 goalkeepers in the K League 1. At 32 Sung-Yun is into the veteran stage, where the age curve weighs on the projection, and a market index of 3.1 reflects that trajectory.

From the career report

Read the full career report →

A career still climbing — Sung-Yun is at his peak right now, and the curve hasn't flattened.

Peak: 2024/25Trending upBreakout: 2024/254 clubs

Current potential8th of 13 goalkeepers · K League 1 Current seasonTop 24% goalkeepers · K League 1 3rd-best goalkeeper in the K League 1 68th in the K League 1 · potential 8th-highest potential goalkeeper in the K League 1

19.1

Ratingi

8th of 13 goalkeepers

31.1

Seasoni

below regular-starter level

40%

Minutes

rotation minutes

Def. actions / 90

light defensive volume

Output in context · FC Seoul finished 1st of 12 · a title-challenging side

Apps

Clean sheets

20%

CS rate

40%

Minutes

5 clean sheets in 25 appearances (20% of games). Playing behind a title-challenging side (1st of 12) means a more protected goal, so the read is about command and distribution as much as raw shut-outs.

Watch points

Game time. Only 40% of available minutes — needs a settled run to prove the level.
Age curve. At 32, both level and resale value are on the downslope.
Level. Rates below a nailed-on top-tier starter on our model.

Outlook

With a Rating of 19.1, Sung-Yun carries the 8th-highest potential of the goalkeepers in the K League 1 of 13. A rotation minutes keeper carrying the gloves this season. Veteran phase — a short-term, lower-fee proposition as both level and value decline (0.8× and falling).

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

Per 90 & availability

Minutes played %40%

Available fixtures25 of 25

Goals / 900

Assists / 900

Goal contribution / 900

Defensive actions / 900

Player flow

Goal involvements0

Pass accuracy %76

Cards / 900.2

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 (~8), then tapers with age. At 32, Sung-Yun sits on 3.1, past its peak and easing. The blue line is Sung-Yun's projected Rating — 19.1 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.

Season statistics

Bars = where he ranks among goalkeepers in the K League 1 with 600+ minutes this season.

Goalkeeping

Clean sheets5

Saves21—

Save rate72.4%—

Goals conceded8—

Distribution

Passes244

Pass accuracy76%—

Yellow/red cards

Yellow cards2

Red cards0

Transfer history

FC SeoulJul 2025 – now

Kyoto Sangauntil Jul 2025

Consadole Sapporo(back from loan)Dec 2023 – Jul 2025

Kyoto Sanga(on loan)Jul 2023 – Dec 2023

Consadole Sapporountil Jul 2023

Daegu FCSept 2022 – Jul 2023

Gimcheon Sangmu FCuntil Sept 2022

Consadole SapporoJan 2023 – Sept 2022

Daegu FCMay 2020 – Jan 2023Free

Consadole SapporoJan 2015 – May 2020

Cerezo Osakauntil Jan 2015

About Gu Sung-Yun

Sung-Yun Gu is a 32-year-old goalkeeper who plays for FC Seoul, born on June 27, 1994 in Pohang, standing 198 cm tall. He is from Korea Republic. FC Seoul currently sit 1st of 12 in the K League 1.

This season

In the current season, Gu Sung-Yun has made 25 appearances with 0 goals and 0 assists across 900 minutes, averaging a 6.77 match rating over his last 9 rated games, with 2 yellow cards.

When Gu Sung-Yun plays, FC Seoul's record this season is 5W-3D-2L.

Recent matches

August 1, 2026: 0-0 draw away at Jeonbuk Motors (90 minutes, 6.8 rating)
July 12, 2026: 0-0 draw at home vs Gangwon FC (90 minutes, 7.7 rating)
May 16, 2026: 2-1 win away at Daejeon Citizen (90 minutes, 6.9 rating)
May 9, 2026: 1-2 loss away at Jeju United FC (90 minutes, 6.5 rating)
April 25, 2026: 2-1 win away at Gangwon FC (90 minutes, 7 rating)
April 18, 2026: 0-1 loss at home vs Daejeon Citizen (90 minutes, 6.7 rating)
April 11, 2026: 1-0 win at home vs Jeonbuk Motors (90 minutes)
April 5, 2026: 1-1 draw away at FC Anyang (90 minutes, 6.3 rating)
March 15, 2026: 2-1 win away at Jeju United FC (90 minutes, 6.7 rating)
February 28, 2026: 2-1 win away at Incheon United (90 minutes, 6.3 rating)

Gu Sung-Yun's next match is on August 30, 2026, when FC Seoul face Gwangju FC away in the K League 1.

Field Insider's view

Field Insider currently rates Gu Sung-Yun at 19.1 with a Season form score of 31.1, ranking 68th of 83 goalkeepers in the K League 1. See the full scout report for strengths, watch-points and the market-value outlook.

His honours include 7 career titles — among them the K League 2 and the EAFF E-1 Football Championship. Full list in the career record.

Career

Across 12 recorded seasons, Gu Sung-Yun has totalled 299 club appearances with 0 goals and 2 assists for 5 different clubs. His busiest campaign came in 2018/19, with 34 appearances for Consadole Sapporo.

Gu Sung-Yun's career has also included time at Kyoto Sanga, Consadole Sapporo, Daegu FC, Gimcheon Sangmu FC and Cerezo Osaka.

On the international stage, Gu Sung-Yun has represented Korea Republic U23 and South Korea — 8 caps in our records.

Transfer news

No transfer news found for this player.

Profile

Season stats

Also this season

Performance data · by competition

Career

Scout report

Output in context · FC Seoul finished 1st of 12 · a title-challenging side

Watch points