It was the final day of the 2009-10 Swiss Super League season, and all eyes were on Seydou Doumbia.

Table-toppers FC Basel were away to second-place Young Boys. With Basel top on goal difference, a draw would give them the title. For Young Boys to claim a first league crown in 24 years, they had to win.

Doumbia was Young Boys' top scorer with 30 goals—the highest tally in the Swiss top flight since 1988—and had scored 11 goals in his previous 10 league outings. If anyone were going to fire Young Boys to glory, it would be him.

The Ivory Coast international lined up at the Stade de Suisse on Young Boys' right flank. He was up against an 18-year-old left-back who was coming to the end of his first season as a first-team player. On paper, it was a mismatch. But Doumbia didn't get a kick.

Valentin Stocker hooked in a pass from Carlitos to put Basel ahead in the 39th minute and then crossed for Scott Chipperfield to double the visitors' advantage just beyond the hour. Tightly shackled by his teenage adversary, Doumbia cut an increasingly frustrated figure, and by the end of the game, he had switched flanks to the left-hand side.

Basel won 2-0, giving them a league title to add to the Swiss Cup they had won a week earlier, and Young Boys were left to contemplate the latest in a long line of agonising near-misses. The name of the youngster who had shut down Young Boys' most dangerous player? Xherdan Shaqiri.

Shaqiri first impressed as a left-back for Basel AFP/Getty Images

"He played against the best player in the Swiss league," Thorsten Fink, Basel's coach at the time, told Bleacher Report.

"We had a 'final' against Young Boys, and he played at left-back against Doumbia. Doumbia scored 30 goals that season, and you didn't see him in that game.

"Shaqiri could play in every position. When I played him at left-back, he played very well. When I played him as a right-winger, he played very well. He could play as a No. 10. At the beginning, I thought he was the best left-back I'd seen. But he wanted to play in attack."

Shaqiri did not play at left-back for much longer. Over the two seasons that followed—first under Fink and then Fink's successor, Heiko Vogel—he emerged as the most exciting young player in Swiss football, the squat, stocky wide player with the bulging calf muscles and booming left foot helping to fire Basel to another league title in 2011 and another league-and-cup double in 2012.

Feeling a natural obligation to help such a talented young player fulfil his potential, Fink urged Shaqiri to improve his off-the-ball work and to show greater dedication to his fitness. From a performance perspective, the bigger the match, the better he played.

"He needs a coach who gives him a lot of trust," Fink said. "Then he can decide a game. In big games, he's there. A lot of players, when they play big games, you don't see them. But Shaqiri loved big games.

"There are players who you try to motivate, and it doesn't help. If you motivate Shaqiri, he flies for you."

Shaqiri's exploits with Basel in the Champions League in 2011-12 moved him into a new dimension. Basel sensationally eliminated Manchester United in the group stage, and Shaqiri played a starring role, setting up both goals in a 2-1 home win over Sir Alex Ferguson's side in December 2011 that turfed the previous season's beaten finalists out of the competition.

He signed for Bayern Munich in February 2012 and joined the club at the end of the season. Despite having been initially seen as back-up for Arjen Robben and Franck Ribery, the Switzerland international played regularly under Jupp Heynckes, scoring eight goals and supplying 13 assists during a maiden campaign that culminated in an unprecedented treble of Bundesliga, DFB-Pokal and Champions League success.

"I think Heynckes let him play a lot because he saw him as a good substitute who could play in nearly every offensive position, and he had a lot of energy that was good to bring in after 60 or 70 minutes," journalist Benedikt Warmbrunn said. Warmbrunn covered Shaqiri's time at Bayern for regional newspaper Suddeutsche Zeitung.

"The fans liked him because he was very outgoing, always friendly, with a smile on his face. The first year was his best in Munich."

Shaqiri's problems at Bayern started when Pep Guardiola arrived in the summer of 2013.

Gero Breloer/Associated Press

Guardiola's style of play obliged his attacking players to move around the pitch in careful coordination with their team-mates, but Shaqiri was a born soloist. Robben and Ribery were always going to be central planks of Guardiola's strategy, and Shaqiri also faced competition from Thomas Muller and new signings Thiago Alcantara and Mario Gotze. A succession of muscle injuries further complicated matters. He finished the campaign having made only 10 league starts.

By November 2014, German newspaper Bild reported that Guardiola had given up hope on Shaqiri and that the winger was "not clever enough" to follow his coach's precise tactical instructions. Bayern had rejected an offer for Shaqiri from Liverpool in the summer, but in January he was allowed to leave for Inter Milan.

"The first season was with Heynckes, who talked a lot with the players, especially young players like Shaqiri. And he played a lot. Then came Pep," Warmbrunn said.

"He needed the trust of the coach and to hear what he had to do and what he had to change to improve. Under Guardiola, he just didn't know where he was."

After a half-season at Inter, Shaqiri joined Stoke City in August 2015, and it was in the Potteries that he would resurrect his career. Not that you would have guessed that from some of the remarks that foreshadowed his departure from the club.

Former Stoke left-back Mike Pejic accused the Swiss of "laziness" and "shirking responsibility." Television pundit Gary Neville declared himself "not a fan" and claimed—rather cruelly—that Shaqiri would just "amble and wobble around" during games. Gary's brother, Phil, went even further, branding Shaqiri a "disgrace." Stoke midfielder Charlie Adam put the boot in once Shaqiri had agreed to join Liverpool last summer, accusing his former team-mate of going missing as the club slid toward relegation.

While Shaqiri acquired a reputation for picking his matches, the statistics showed that he was one of Stoke's most effective players. He scored or created 43 per cent of their 35 goals in the Premier League. It was his most productive season since his final campaign at Basel.

Shaqiri angered some Stoke fans toward the end of last season when he gave an interview to Swiss magazine Schweizer Illustrierte (translated by the Stoke Sentinel, via Joe.co.uk) in which he complained about the "lack of quality" in the squad and said that "even a Ronaldinho" would be powerless to prevent the team's slide toward the Championship. Shay Given, Stoke's former goalkeeper, said he felt like putting Shaqiri "in a headlock" after reading his comments.

But Martin Spinks, who reports on Stoke for The Sentinel, felt some sympathy.

"You could hardly blame him because, like many other players, he deserved better than Stoke City could offer him in the latter stages of the Mark Hughes reign," Spinks said. "To be fair to Shaqiri, his performances at that precise time didn't raise particular doubts about his devotion to the cause."

Shaqiri had been one of the symbols of Stoke's intended direction of travel under the management of Hughes. The attacking trident he formed with Marko Arnautovic and Bojan Krkic gave the club hitherto unimaginable allure and hinted at a sparkling future, not least in December 2015 when Manchester City and Manchester United were each condemned to 2-0 defeats at an exultant Britannia Stadium.

Gareth Copley/Getty Images

That dream had died by the middle of last season, and although Shaqiri responded positively to the indulgence granted him by Paul Lambert, Hughes' successor, it was not enough to keep Stoke in the division.

"There's no doubt he responds to a bit of love, something Paul Lambert gave him in spades during that battle against the drop, but he also responds to the knowledge he has good players around him," Spinks said.

"In a struggling team, you suspect his chin can drop a little too quickly."

At Liverpool, Shaqiri appears to have found the perfect combination of carrot and stick: an ambitious team full of top-level performers, overseen by a manager who can come down like a ton of bricks when needed.

Jurgen Klopp has been tough on Shaqiri at times—witness the on-pitch dressing-down he received after Liverpool's Carabao Cup elimination against Chelsea—but the 27-year-old has responded positively. Per Sky Sports, Opta stats show he ranks second only to Mohamed Salah for possession won in the attacking third per 90 minutes for Liverpool this season, and in October's 1-0 win at Huddersfield Town, he covered more ground than any other visiting player.

OLI SCARFF/Getty Images

"I get on really well with him," Shaqiri said of Klopp in an interview with Blick (in German) in November. "I like people who are open like that. And the fact we can chat in German is obviously great, too.

"Klopp has such an impact on me that it makes me think: 'I want to win the title for this man.'"

Shaqiri has scored four goals in his past four appearances and secured a small portion of Anfield folklore in December with a match-winning brace in front of the Kop against Manchester United. With Liverpool gunning for glory on three fronts and Switzerland two games from victory in the inaugural UEFA Nations League, 2019 could be the year he finally proves himself as a match-winner at the highest level.

At the very least, he's unlikely to find himself playing at left-back anytime soon.