Antoine Griezmann apologised to Atletico Madrid's fans for the "hurt" he caused them by leaving the club, after scoring the only goal in their 1-0 LaLiga win at Athletic Club on Saturday (stream the replay on ESPN+ in the U.S.).

Griezmann's return was made permanent on Monday -- signing a contract until 2026 -- after Atletico and Barcelona agreed a €20 million transfer fee, ending a dispute over the forward's loan agreement which saw him used as a substitute for most of this season.

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Under the terms of the two-year loan agreed in 2021, Atletico were due to pay €40m if the player featured for over 45 minutes in 50% of the games for which he was available, leading the club to order manager Diego Simeone to keep him on the bench in an attempt to force Barca into a compromise.

Griezmann upset Atletico fans by leaving for Barca in 2019 in a €120m deal -- before failing to settle at Camp Nou and rejoining on loan two years later.

"I'm very proud to have finally been able to get to this point, to be able to renew [my contract] and to be an Atletico player completely," Griezmann said on Saturday.

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"I apologise. I know that a lot of people want to hear it directly from me. I'm sorry if I hurt the fans, but the biggest apology I want to make is on the pitch."

The France international has started six of Atletico's nine LaLiga games so far this season on the bench, but played for the full 90 minutes in the victory at San Mames that saw them move up to third in the table.

"[Not starting games] was difficult personally, but I tried not to show it," Griezmann added. "When I play, I give 100%, and if not I support my teammates and make a difference when I come on."