"There's been a big change inside this stadium." Atletico Madrid have just fought back from 1-0 down to beat Villarreal 3-1 and, just a short distance inside the tunnel, the applause of the home crowd still ringing around the Estadio Metropolitano, Antoine Griezmann is talking to ESPN.

Griezmann, 32, created the equaliser and scored Atletico's crucial second against Villarreal. With that goal, he drew level as the club's all-time joint-second highest goal scorer -- 169 goals, with Adrian Escudero -- and helped give Atletico a club-record 15th consecutive home league win.

Even when trailing in the LaLiga game on Nov. 12, the fans didn't stop singing. A few days earlier, Atletico had beaten Celtic 6-0, the club's biggest Champions League win. The vibes at the Metropolitano are good.

"When the fans are like that, it's a plus," Griezmann told ESPN. "When you're really tired, in the 80th minute, they're the ones who push you. They've brought a different atmosphere to this stadium. They make you want to give everything. And you can see it in the results."

Since a difficult start to the 2022-23 season -- which coach Diego Simeone called the most difficult period of his 12 years in charge -- Atletico's fans have gone 10 months without seeing their team lose at home. Griezmann's contribution to that streak has been fundamental; for many, he's been the best player in LaLiga this calendar year.

Two weeks after the Villarreal game, he scored again in Saturday's 1-0 defeat of Real Mallorca. Another goal, another home win and another opportunity for the crowd to sing Griezmann's name.

Not long ago, his relationship with those fans looked beyond repair, their hearts broken by Griezmann's 2019 signing for Barcelona. Now, Atletico's hopes of getting a result at Barca on Sunday -- a match they go into level on points with Barca, with a game in hand -- rest on his shoulders.

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The way Griezmann has rebuilt his connection with those fans, and rediscovered his form, since his return to Atletico has been a comeback to match any in LaLiga.

Let's start with the obvious: Griezmann's move to Barcelona didn't go as planned. The switch -- which he publicly agonised over in his "The Decision" documentary in 2018, before finally making the leap a year later -- wasn't as disastrous as you remember. He did manage 22 league goals in two seasons -- 35 in all competitions -- but there was no natural place for him in the Barca team. After all, his preferred playmaker role was occupied by the best to ever do it, Lionel Messi.

In 2021, with Barcelona desperate to free up space on their wage bill, the time came for Griezmann to cut his losses and move on. But rejoining Atletico wasn't inevitable. Would the fans take him back? Wouldn't it be better to start fresh somewhere else?

Despite two underwhelming years in Barcelona, there was no shortage of interest from elsewhere. But for Griezmann, Atletico were the only choice. It was the club where he had become the best version of himself and had a manager in Simeone who believed in him unreservedly. The French international was even willing to take a substantial pay cut to make it happen, and the last-minute deal was announced after the window closed on transfer deadline day, at 1.23 a.m. local time on Sept. 1, 2021.

"Barcelona and Atletico Madrid have reached an agreement for the loan of Antoine Griezmann for a season, with the option of a further season," Barca said. "The Madrid club will pay the player's wages and there is a compulsory permanent transfer clause."

Getting back to Madrid was only the beginning. Now Griezmann had to win over the fans.

Some of them had chanted "Griezmann, die" the first time he returned to the Metropolitano with Barcelona. Some had left toy rats on the plaque that bears his name outside the stadium. Others held up a banner attacking his motivation for leaving: "You wanted to have a name and you forgot to be a man."

Griezmann knew that words or gestures wouldn't be enough to restore fans' trust. He would have to do that on the pitch, though his performances in that first season back didn't help. Griezmann scored just three goals in 26 LaLiga appearances for Atletico in 2021-22, the worst return of his career.

Inhibited by injuries and short of confidence, he was feeling the pressure. "Personally, I've been a bit pissed and annoyed," he told ESPN in May 2022. "I'm not scoring and I know the team -- and everyone -- need my goals. [Not scoring] is something that can't happen. ... I feel good in general, but what I'm missing is goals. They're a necessity for the team. And I need them too. That's the only thing I'm missing."

The 2022-23 season was an opportunity for a fresh start, but a complicating factor well beyond his control threatened to undermine Griezmann's ability to get back on track.

Atletico were aware that if he played at least 45 minutes in 50% of the games for which he was available over the two seasons of his loan, the "compulsory permanent transfer clause" would kick in and they would be obliged to pay Barca a 40m transfer fee. Given his form over the previous year, Atletico didn't want to do that, so the club settled on a brazen solution. They asked a reluctant Simeone to bench Griezmann and bring him on as a second-half substitute, with around an hour played, week after week. Both player and coach had no choice but to make the best of it.

In nine games (seven in LaLiga, two in the Champions League) between August and October 2022, Griezmann was used as a substitute. Predicting in which minute he would be introduced -- the 62nd, the 64th, the 63rd or the 60th, never too early in case added time risked breaking the 45-minute threshold -- became a running joke. Meanwhile, Griezmann kept his head down, handling the unprecedented situation with an admirable professionalism. When asked about it in September 2022, Simeone was cryptic, but left no doubt where responsibility lay: "I'm a club man, and I always will be."

Atletico's aim was to scare Barcelona into thinking that they might be willing to keep this up, the clause might not be activated, Griezmann's loan wouldn't become permanent and Barca would be forced to take the player back. The gambit worked: the two clubs reached a compromise, with Griezmann's help as intermediary, and on Oct. 22, 2022,Atletico confirmed the signing of Griezmann for a 20m fee, half of what the club were originally due to pay.

A year later, it looks like the bargain of the century. Griezmann was encouraged by the universal acclaim he received playing for France at the 2022 World Cup in Qatar, starring in an unfamiliar, unglamorous midfield role as Les Bleus surged all the way to the final, where they lost to Messi and Argentina in a seven-goal thriller.

He returned to Spain rejuvenated: Griezmann scored 10 league goals between January and May 2023, twice as many as he had in the first half of the season. He ended 2022-23 with 15 goals and a league-high 16 assists. No player in LaLiga played more key passes (84) or contributed more shot-creating (162) or goal-creating (26) actions.

By the end of the season, Atletico's fans had seen enough. They started singing his name again.

More introverted than his dyed hair and exuberant goal celebrations might suggest, Griezmann has been open about the way his emotional well-being dictates his performances.

"I need to be happy off the pitch to be happy on it," he told Marca last week, after a fans' poll named him 2022-23's most decisive player. "My teammates help with that, the boss, the physios, the kitmen. ... There's good chemistry with them. And I've been getting my connection with the fans back. Now you can see that I'm happier, playing with more freedom."

In the summer, there was interest from Saudi Arabia -- of course -- but Griezmann didn't entertain it. Speaking to ESPN in August, his priorities were clear. He is keenly aware of having missed out on Atletico's two LaLiga titles in the past decade, joining after they won the league in 2014 and returning after they won it in 2021. "I haven't won the league or the Champions League," he said. "I want to make history at Atleti and that means I need to win trophies. It would be a dream to win the Champions League.

"For me personally it's about improving on last year, scoring 16 or 17 goals. That would make me the top scorer in the club's history, which is something that excites me."

So far, so good. At the time of writing, Atletico are four points off the top of the LaLiga table, with a game in hand. They have comfortably qualified for the Champions League round of 16 with a game to spare. And they have scored more goals at this stage of the season (45) than at any time in the 12-year Simeone era.

Griezmann has scored 13 times already, with nine goals in LaLiga. He's now on 170 goals for Atletico, two behind the record holder, Luis Aragones. Breaking that record will underline his name in Atletico Madrid's history, but to earn the recognition he truly deserves, he needs another major trophy to put alongside his 2018 World Cup and Europa League. Simeone knows it too.

"[Griezmann] is an extraordinary player," the coach told El Larguero this month. "He's won over the fans. If you make a mistake, you apologize. After that he showed what he had to show. It's not about talking, it's on the pitch, that's what matters to the fans. ... [To win the Ballon d'Or?] We have to win something big. If not, it's difficult. Winning something big changes things."

The outcome of Atletico's visit to Barcelona on Sunday will suggest which of the two teams is best placed to join Real Madrid and Girona in the fight for the LaLiga title. If Griezmann's mood is a barometer of performance, he's as likely as any player to be decisive.

"I'm really happy," he told ESPN, back in the tunnel after the Villarreal game, still breathless after another selfless display of non-stop running, the most ego-free, hardworking star player you've ever seen. "I'm happy with what I'm doing. And the most important thing is that the team is winning. Let's hope it continues."

With additional reporting by Rodrigo Faez.