Striker Antoine Griezmann says he struggled to adapt to life again at Atletico Madrid after returning to the La Liga champions from Barcelona last summer.

The France international shone this week in Atletico’s dramatic 3-1 win away to Porto to secure a place in the Champions League last 16, but he and the team have been at odds this season.

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Atletico will play the derby on Sunday, 10 points behind Real Madrid, behind their rivals in the La Liga table.

“To be honest, it was very difficult for me at first,” Griezmann told ESPN. “It was a rhythm I wasn’t used to, a new system for me. I had to take that and mix it up with my own style of play.

“Finally I’m getting better, and I’m feeling better on the pitch. Getting to the next round of the Champions League was very important to me.”

Griezmann, 30, spent five years at Atletico – becoming the club’s fourth-highest goalscorer – before a controversial move to Barcelona in 2019.

After two choppy seasons at Camp Nou, he returned to the Wanda Metropolitano in August on a season-long loan, with Atletico committed to making the deal permanent next summer.

His contribution to LaLiga has been inconsistent thus far, scoring three goals in 12 matches, but he played a key role in Atletico’s progression from Group B in the Champions League, scoring four times including the opening game in the must-win game against Porto.

Atletico’s victory in Sunday’s derby would put them within seven points of leaders Real Madrid with a game in hand.

“At the end of the day there are three points at stake,” Griezmann said. “I don’t think it really matters how many points they have, because it’s a really long season, we saw that last year… We still have to fight for the title until the last game.

“I think we can take something from that. There is still a lot of league left and a lot of games left to play.”

Diego Simeone’s side faces a defensive injury crisis, with four of the seven defenders out – Stefan Savic, Jose Maria Jimenez, Kieran Trippier and Sim Vrsaljko – while striker Luis Suarez is also in doubt.

Real, also awaiting the fitness of striker Karim Benzema, have won their last nine matches in all competitions.

“Real Madrid has been one of the best teams in the world for many years,” Griezmann added. “They’ve always been there. It’s a derby for us, so it’s very important for the fans and the club. You play for the pride of every club. It’s going to be a great match to watch.”