After retiring as a player, Yalçın transitioned into management, taking charge of several Turkish clubs before returning to Beşiktaş as head coach in 2020.

In his first full season, he led the club to a historic domestic double, winning the Süper Lig and the Turkish Cup.

Sergen publicly criticised Zeman for trying to play him on the wing, which he believed was not his best position, and was accused of faking injury to avoid training sessions.

Due to his terrific individual showings for the Turkey national football team, Sergen attracted attention from several foreign clubs.

While casinos were banned on the Turkish mainland, they remained open in Northern Cyprus, which attracted quite a lot of gambling trade from Turkey.

When he returned to Istanbul, he told manager Fatih Terim he was tired from the journey and asked if he could skip a training session.

Sergen had never yet played for a club outside Istanbul, and it was believed that removing him from the distractions of the big city would do good for his appalling disciplinary record.

British coach Gordon Milne, who worked with him at Beşiktaş, also despaired of trying to get Sergen – and his magical left foot – to the training ground on time.

[9]The move was rewarded as Sergen repaid his manager’s faith by starring in the UEFA Champions League with two goals and two assists as Galatasaray progressed to the second group stage.

After elimination from the UEFA Champions League, Mircea Lucescu insisted that if Sergen had remained fit, Galatasaray would have gone on to win the tournament.

The 2003–04 season marked Beşiktaş’ return to the UEFA Champions League, where Sergen featured in arguably the most memorable match of his career.

[10] Although Beşiktaş was eliminated in the group stage, Sergen once again proved his class by scoring two goals and providing three assists in six matches.

After winning the ball near the midfield, he initiated a brilliant solo run that ended with an assist to İlhan Mansız, who finished the move with a goal.

[11] Before the 2006–07 season, manager Jean Tigana did not see Sergen as part of his future plans, and as a result, Beşiktaş terminated his contract with immediate effect.

The next match against Moldova, Sergen was the maestro for the Turkish side, with his spectacular dribbling runs, shots at goal and his clairvoyant passes creating scoring chances for his teammates.

The final game with Germany ended 0–0, but is seen as one of the greatest individual displays in the history of the Turkey national team, as Sergen "pulled all the strings", according to the German manager Erich Ribbeck.

Sergen Yalçın may play Fenerbahçe, but his midfield display was an unscheduled replacement for the top of the bill showing we’d been expecting from the Manchester United man.

Yalcin, without ever moving faster than a jogger, was always one step ahead, showing the ball to Keane like a matador brandishing a cape and then whisking it away as his dangerous foe arrived.

In the first 20 minutes of the second half alone, Sergen set up four clear scoring chances as he produced another man of the match performance.

The bizarre interpretation of the shoulder-charge ruling by the Scottish referee Hugh Dallas may have presented Italy with the penalty that pushed Turkey to defeat in their opening Group B fixture, but Sergen's contribution was immense, an intoxicating cocktail of neatly threaded through-balls and passes so visionary they might have been delivered by Mystic Meg.

His transfer to Galatasaray and performances in the UEFA Champions League allowed him back into the team and he featured in the 5–0 thrashing of Austria to qualify for the 2002 FIFA World Cup.

Sergen again wasn't involved in most of the UEFA Euro 2004 qualification campaign, but due to his memorable performance against Chelsea, he was selected for the crucial final qualifying match against England.

However, he resigned in December 2009, citing head coach Mustafa Denizli’s lack of interest in youth development and reluctance to utilize young players.

[25] On 24 October 2015 after a 2–0 defeat against Trabzonspor Yalçın announced he was considering resigning due to poor performance and subsequently mutually terminated his contract.

During his tenure in the Süper Lig, Sivasspor played 29 matches under Yalçın, winning 7, drawing 11, and losing 11, scoring 40 goals while conceding 41.

[30] On 25 September 2017, after failing to secure a win in the first five league matches and with the team sitting in 17th place with just 3 points, Yalçın resigned.

During his six-month tenure, Yalçın oversaw 17 league matches, achieving 6 wins, 6 draws, and 5 losses, with the team finishing the first half of the season in 8th place.

However, following poor domestic performances and disappointing results in the 2021–22 UEFA Champions League, where the team finished last in their group with zero points, Yalçın decided to resign.

His father, Özer Yalçın, a former footballer, recognized his talent early and took him to Beşiktaş for tryouts, entrusting him to Serpil Hamdi Tüzün.

He also took on a leading role in the TV series "Sil Baştan," produced by Tükenmezkalem Film and directed by Gani Müjde, alongside Emre Kınay, Dilara Gönder, Esra Dermancıoğlu, Belma Canciğer, and Murat Dalkılıç.