Merlín, the duck that has become an unlikely World Cup sensation in Mexico, made a much-anticipated trip to the stadium on Wednesday but was not allowed to stay for Mexico’s match against the Czech Republic due to FIFA regulations.

The two-year-old duck has become a social media star after appearing alongside his family during Mexico’s opening World Cup victory. His popularity has grown rapidly, prompting fans to campaign for him to be allowed inside the stadium for the national team’s match.

Merlín arrived at Azteca Stadium with his owner, Carla Gómez, and her son Cristian. He was allowed onto the stadium grounds to take part in a television segment for Televisa, one of Latin America’s largest broadcasters.

Transported in a special crate and accompanied by security personnel, the duck attracted attention from fans eager to catch a glimpse of the tournament’s most unusual celebrity.

However, FIFA rules prohibit animals from entering stadiums during matches, citing animal welfare and safety concerns. As a result, Merlín was not permitted to remain inside the venue for the game.

A FIFA spokesperson confirmed that the duck was allowed into the outer stadium area but could not enter the stadium itself.

Gómez said the attention Merlín has received in recent days has been overwhelming.

“The last few days have been incredible. We are very grateful for everything that has happened. People are amazed by Merlín,” she told AP.

Dressed in a green Mexico football jersey, Merlín has become a familiar face around Mexico City, where he accompanies his family as they sell drinks. His growing fame has led to television appearances, interviews, visits to fan events and even a stop at Netflix’s offices.

Many supporters now view him as an unofficial mascot for both Mexico and the World Cup.

“He’s become our unofficial mascot,” said fan Daniel Krauze outside the stadium. “I’m proud to support Merlín the duck.”

The bird’s popularity has even sparked a legal dispute over commercial rights to his name. According to reports, others attempted to register the Merlín trademark before Gómez, but the rights were eventually awarded to her.

Although Merlín could not watch the match from the stands, his family was finally able to attend a Mexico game after receiving hundreds of invitations and messages from supporters.

Gómez remains convinced that the duck brings good luck to Mexico’s national team.

“Merlín is a lucky charm,” she said. “I believe Mexico will win again today with his support.”