Barcelona were under the cosh. As the clock ran down in their La Liga match against Rayo Vallecano earlier in November, the Catalan side trailed 2-1.

Enter Ousmane Dembele.

In the 86th minute, he got on the end of a knockdown by Gerard Pique and cracked home a half-volley to tie the game, which Luis Suarez added to with a winner in the final minute of normal play.

The young French winger wheeled away in celebration after his goal, punching the air. As he landed on the ground, he turned to receive the acknowledgement of his team-mates. None of them came to celebrate with him. Not even a wink or a wave, so he ambled back discretely to the halfway line. So much had changed.

In the Spanish Super Cup final in August, after Dembele scored a scorcher from outside the box to win the match 2-1 against Sevilla, he celebrated by jumping into the arms of Suarez before being engulfed by several other team-mates, including Lionel Messi and Sergio Busquets. The love-in appears to be over.

Following an impressive start to the season in which he scored five goals in six games, Dembele's performances began to taper off. After starting Barcelona's first nine games, he was an unused substitute for the club's UEFA Champions League tie against Tottenham Hotspur at Wembley Stadium.

Coach Ernesto Valverde turned to Dembele a couple of weeks later, however, when Messi fractured his arm early into a match against Sevilla in the league at the Camp Nou.

Messi went down in the 16th minute of the game. It took Dembele a further six minutes to enter the fray. According to an El Pais report that highlighted some of Dembele's key issues, his dawdling enraged his team-mates

After the game, the mild-mannered Ivan Rakitic appeared to make a pointed reference to it when he said: "Today we played a lot of time with one less player."

When Barcelona's squad gathered for their next training session on Camp Tito Vilanova at the club's sports campus, one of the coaches told them that those who started against Sevilla and Dembele would do a recuperation session while the rest of the players would train.

One of the team's heavyweights reportedly quipped: "Dembele played?" The squad burst into fits of laughter.

Dembele got off to a bad start last season. The Frenchman has struggled to learn Spanish. He missed a good chunk of the campaign through injuries and inconsistent form, and he has found it difficult to blend into the team's renowned tiki-taka style of play.

"There is a basic problem," Ramon Besa, a journalist with El Pais, told Bleacher Report. "Dembele is a free-verse footballer, a loose player, who is playing in a very sophisticated team with a very determined theory of how the game should be played, which is instilled from a young age in its players at La Masia. If you can't interpret well the way in which Barca plays, you will have problems. He is finding this out.

"It happens to all the players who are formed on the street. Remember, for example, the cases of Hristo Stoichkov or Zlatan Ibrahimovic. And, on the other hand, you have the likes of Bojan, who could assimilate into the first team. Samuel Eto'o as well adapted but he clashed with Pep Guardiola—when Guardiola was manager—and in the end he was traded. You have to know how to read the midfielders' game, and to decipher how possession-based football works."

Dembele's price tag has cast a shadow over him, too. He landed at the club in August 2017 as the most expensive player in the club's history (a mantle later taken by Philippe Coutinho) in a flurry to fill the void left by Neymar Jr., who had sensationally joined Paris Saint-Germain a few weeks earlier.

Few 20-year-olds living in a foreign country could adjust to that pressure. He has the hallmarks of repeating the nomadic career paths of wayward talents like Nicolas Anelka and Mario Balotelli.

Dembele, of course, hasn't helped himself. He's been childish, complaining about the driver the club assigned to him and eating junk food. He's lacked commitment to the club's commercial duties and repeatedly been unpunctual. For example, according to Diario Sport, he turned up 25 minutes late for Barcelona's home tie in October against Inter Milan in the UEFA Champions League.

"Dembele has the same problems at Barcelona as he does with the France national team," Miguel Rico, a columnist with Mundo Deportivo, told B/R. "Remember that [France manager] Didier Deschamps in practically every press conference reminds us that Dembele has problems adapting to professional football. So I understand the problem to be with Dembele.

"I think players are difficult everywhere you look. [For example] Karim Benzema at Real Madrid has had many problems with fast cars. His driver's license was taken from him. He had this problem where he was investigated [and dropped from the France national team because of a blackmail case].

"There have always been difficult players. What has happened is that now there are more media outlets, more scrutiny. The press know more things about players' lives. All through history there have been anarchic footballers—that struggle to adapt to any situation or environment that is different to the one they are used to."

The local Spanish press have criticised the company Dembele keeps. They blame his entourage—a cadre of childhood friends from the French suburb in Normandy where Dembele grew up with has now followed him to Barcelona.

On the Thursday before Barcelona's most recent league match—a 4-3 defeat to Real Betis at the Camp Nou—Dembele went AWOL. Barcelona's training that morning began at 11 a.m. There was no sign of Dembele. The club tried to contact him. His phone was on silent. Eventually, 30 minutes later, club delegate Carles Naval got through to him, per Sport. Dembele explained he was suffering from gastroenteritis. 

When a doctor called to his house half-an-hour later to assess him, the blinds on his house were drawn. Most of Dembele's friends were asleep in the house. The doctor couldn't detect anything wrong with Dembele and told him to rest for the day.

The worry is that Dembele is more interested in playing PlayStation than with Barca. As well as lacking professionalism off the pitch, he's displayed a brainlessness and lack of patience on the football side. 

"Dembele has the coach, Valverde, who is on his side," says Besa. "He's given him chances as a starter. He's shown him votes of confidence, but Dembele can't handle being a substitute. Dembele is the epitome of talent without effort. He believes that he should not have to make an effort—that he can impose himself simply because he's better than anyone else in the game. He dominates space, but not always at the right time—how to make the best decisions in each moment, when to shoot, to pass, to cross."

Barcelona is keen to make the Dembele project work. According to Mundo Deportivo, the club's hierarchy, including club president Josep Maria Bartomeu and director of football Eric Abidal, met with his agents to try to get them to encourage the 21-year-old to apply himself.

Abidal is an important mentor for Dembele, with more potential influence than Valverde, team captain Messi or Samuel Umtiti—Dembele's closest friend in the squad and a fellow FIFA World Cup winner with France. 

"Eric Abidal is the most important person for Dembele," says Rico. "He speaks the same language. He has spent a lot of time in Barcelona. He has also been an international French player. He knows the ambience of the France national team, and it's his responsibility as Barcelona's director of football to look after Dembele. I'm pessimistic about his chances of success, though, because I think in life there are types of people who can't be helped, who don't take advice. And it seems Dembele is one of these people who can't be helped."

Josep Maria Minguella, the agent who brokered the deals that brought both Diego Maradona and Messi to Barcelona, argued on Cadena Cope that Barcelona missed a trick in choosing Dembele over Kylian Mbappe to replace Neymar Jr. in the summer of 2017.

Mbappe's father told Minguella his son would love to play with Messi. Minguella offered Mbappe to Barcelona, but they never responded to his proposal. A few weeks later, the club signed Dembele instead.

"The technical staff at Barcelona thought that for the system of the game they play, Dembele would suit better," says Minguella. "For me, there is no doubt that Mbappe is a player with a lot more possibilities than Dembele, but I don't decide these things." 

The club has no choice but to persevere with Dembele despite the growing lack of patience with his attitude. "I think that all of Barca's squad [including Messi] is annoyed with the behaviour of Dembele," says Rico. "This is the worst thing that can happen to Dembele—that the team gets tired of him."

Despite Dembele's insubordination, it would be inconceivable that the club would sell him during the winter transfer window, although they might cut their losses next summer depending on his behaviour for the rest of the season and whether a wealthy English Premier League suitor shows an interest in him. For now, Valverde—who is light on goalscoring players—needs him.

"Barca still counts on him as a player," says Minguella. "He has such good quality, and they paid a lot of money for him so they will do as much as they can to salvage the situation."

Follow Richard on Twitter: @Richard_Fitz