Gu Sung-Yun

Following his move to FC Seoul, Sung-Yun's current-season form is up 650% on last season (Season 4→30), while his Rating climbed 15→21. 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	32	7	22%	5.67	19	30
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 32 appearances, a Season grade of 30, top 13% of K League 1 goalkeepers. On long-term scout potential he's rated 20.5, ranking 113th of 153 in the K League 1. A seasoned veteran, he has been a rotation option (50% 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 30 — an excellent campaign that ranks top 14% of the 15 goalkeepers in the K League 1, on 7 clean sheets across 32 appearances.

Year-on-year, that's a clear step up on last season (Season 4 → 30). Across the 6 seasons we hold, it's his best return yet.

On long-term talent our Rating reads 21, 9th of 15 of the 15 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 3.3 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: 2026/27Trending upBreakout: 2024/254 clubs

Current potential9th of 15 goalkeepers · K League 1 Current seasonTop 14% goalkeepers · K League 1 2nd-best goalkeeper in the K League 1 113th in the K League 1 · potential 9th-highest potential goalkeeper in the K League 1

20.5

Ratingi

9th of 15 goalkeepers

30.2

Seasoni

below regular-starter level

50%

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

22%

CS rate

50%

Minutes

7 clean sheets in 32 appearances (22% 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 50% 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 20.5, Sung-Yun carries the 9th-highest potential of the goalkeepers in the K League 1 of 15. 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 %50%

Available fixtures32 of 32

Goals / 900

Assists / 900

Goal contribution / 900

Defensive actions / 900

Player flow

Goal involvements0

Pass accuracy %77

Cards / 900.125

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 3.3, past its peak and easing. The blue line is Sung-Yun's projected Rating — 20.5 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 sheets7

Saves30

Save rate78.9%

Goals conceded8

Distribution

Passes374

Pass accuracy77%

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 2015 – Sept 2022

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 32 appearances with 0 goals and 0 assists across 1,440 minutes, averaging a 5.21 match rating over his last 10 rated games, with 2 yellow cards.

When Gu Sung-Yun plays, FC Seoul's record this season is 8W-4D-4L — and his match ratings average 5.3 at home against 5.86 on the road.

Recent matches

October 18, 2026: 2-2 draw at home vs Gimcheon Sangmu FC (90 minutes, 6 rating)
October 10, 2026: 2-1 win at home vs Jeju United FC (90 minutes, 6.1 rating)
September 20, 2026: 1-2 loss away at Pohang Steelers (90 minutes, 6 rating)
September 12, 2026: 2-1 win away at Jeonbuk Motors (90 minutes, 6.1 rating)
September 8, 2026: 0-1 loss away at Ulsan Hyundai FC (90 minutes, 0 rating)
September 5, 2026: 1-0 win at home vs Incheon United (90 minutes, 0 rating)
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)

Gu Sung-Yun's next match is on October 28, 2026, when FC Seoul face Viettel away in the AFC Champions League Two.

Field Insider's view

Field Insider currently rates Gu Sung-Yun at 20.5 with a Season form score of 30.2, ranking 113th of 153 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 306 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