JUST as Barcelona head into their biggest week of the season so far, their big summer signing Antoine Griezmann is facing the greatest challenge of his career.

After all the drama of his 12 months delayed arrival from Atletico Madrid last July, Griezmann seemed at home at the Camp Nou when he scored twice in August’s 5-2 La Liga victory over Real Betis, then showed off a glittering celebration imitating NBA star LeBron James.

But the gloss has come right off the €120 million attacker, with just two goals in 14 Barca games since then. He has played all across the front line during his first four months, looking uncomfortable and increasingly short of confidence whether out on the wing, as the centre-forward, or drifting deeper into midfield or even full-back.

Antoine Griezmann:

"I try to understand the philosophy of the club as quick as possible because the team needs me but sometimes it is difficult.

When I get the ball I have a certain lack of confidence in when to pass or when to shoot on goal. I don't know how to dribble." pic.twitter.com/McWJG4Hwsi

— Football Tweet (@Football__Tweet) November 26, 2019

It is not that Griezmann is not trying his best to contribute. Probably his most significant game since joining was at Levante in early November, when he showed all his Diego Simeone-trained workrate and even made a couple of important blocks back in his own penalty area. He also missed a gilt-edged chance at the other end though, and Barca lost 1-3.

The biggest issue is – as so often with new attacking players at Barca – how to fit with what Messi wants to do. With Luis Suarez less mobile than ever at number nine, and their Argentine number 10 needed back in midfield to get moves going, Barca need someone to make the right runs to stretch the play and get in behind opposition defences.

Griezmann's instinct is to get forward as quickly as possible, as encouraged by Simeone at Atletico and Didier Deschamps with France. While Messi [and Sergio Busquets] prefer to slowly build moves, reposition their own team and slowly pull the opposition defence out of position. Ernesto Valverde in theory probably leans towards Griezmann’s more direct ideas, but the coach's influence on how Barca are currently playing is questionable.

“Griezmann is coming from another style of play, where he ran into space a lot,” Valverde said recently. “Our moves take longer, the timing is different. He is very generous and keeps making his runs, always wants the ball. But they are different styles. We have to get used to each other, to be patient.”

Valverde was speaking before Barca hosted Celta Vigo at the Camp Nou, and his words proved prophetic as Griezmann and Messi exchanged a total of zero passes during the first 45 minutes of a game the club captain basically won himself with a penalty and two long-range free-kicks.

️ — Griezmann: "I'm really shy and I don't feel comfortable going up and talking to people. I'm not someone who starts a conversation but Luis Suárez, Messi and I are beginning to learn about each other. We've already had dinner together." pic.twitter.com/cdpGNZoZlA

— Barca Universal (@BarcaUniversal) November 24, 2019

The following midweek came the shock 0-0 Champions League draw at home to Slavia Prague, in which Messi gave just three passes to Griezmann, and Griezmann found Messi just once with the ball all game. It was clear that they were just not on the same wavelength.

The 2018 World Cup winner is not the first big name attacker to not immediately settle at Barca. David Villa, Alexis Sanchez and Neymar all managed to change their natural game to different degrees, before eventually leaving for more prominence elsewhere.

With Messi and Suarez now both well into their 30s, the idea is for Griezmann to stick around and become a central figure of a new era. Along with last summer’s other big signing Frenkie De Jong, he was supposed to reinvigorate Barca’s play, and lead a new more direct but equally successful team. Instead Valverde’s side are regressing and the current consensus among purist blaugrana pundits is that the team has “forgotten how to play football”, and are now almost totally reliant on either Messi genius or set-pieces for goals so far this term.

Griezmann was again peripheral in Saturday’s fortunate 2-1 La Liga victory at bottom team Leganes. Ousmane Dembele was [Messi aside] Barca’s brightest attacker, and Griezmann was replaced by teenager Ansu Fati before the hour mark, having never threatened to score. Both goals came from Messi delivered set-pieces.

[MARCA] | Valverde's MSGD front 4 fails to work.

Despite the attack looked threatening on paper, the team's layout led to Suarez often finding himself isolated up front and it failed to give Messi the freedom he needed.Griezmann and Dembele were equally ineffective out wide. pic.twitter.com/wRHnMLhrdl

— BarçaTimes (@BarcaTimes) November 25, 2019

Griezmann could well be benched for Wednesday’s crunch Champions League group game at home to Dembele's old team Borussia Dortmund, where Barca really need to win given slip-ups earlier in the group. And / or for Sunday’s return to Atletico’s Wanda Metropolitano, where the majority of rojiblanco supporters would enjoy any discomfort on their former player’s part.

Just as he has not hidden on the pitch, Griezmann has showed up regularly for mixed zone interviews, and can be winningly self-critical when facing questions. “I have to take it slowly,” he said after the Levante game. “It happened to me at Atletico, and is happening again at Barca. I am not going to pick up the tactics instantly. I am used to all this.”

It is true that Griezmann has overcome plenty of challenges over his career, from being rejected in France for being too small by Lyon to being in and out of the Atletico team for months following his €30 million arrival from Real Sociedad in 2014. Then it all clicked with a hat-trick at his old club's rivals Athletic Bilbao in December. The lessons learned during his difficult settling in period under Simeone proved key as he emerged as a more effective all-round player. This week would be the ideal time for it all to click for Griezmann at Barca.