Mingueza bid an emotional farewell after four seasons at Balaidos, publishing an open letter on social media after the two sides failed to agree terms on a new contract following the expiry of his deal on June 30.
"I arrived in Vigo with the excitement of starting a new adventure. A city and a club that welcomed my wife and I with open arms. From the first day I felt the pride and responsibility of wearing the sky-blue shirt," he wrote.
The Catalan defender reflected on Celta's progress during his time at the club.
"I have always tried to give my best, with maximum enthusiasm, to defend this badge. I leave calm and happy to have been part of this group, this family, a group that has written a page in this club's history by returning Celta to European competition for two seasons running. How beautiful it has been to live through European nights at Balaidos, listening to the Centenario anthem."
He also thanked the club's supporters directly: "After four seasons, all I can say is thank you. Vigo has become more than a city, it has become a home, where our two children, Bruna and Luca, were born. There will always be a little piece of our family that belongs to this land.
"I want to thank all my team-mates, coaches, coaching staff, physiotherapists, kit staff and everyone who works at this club for making our daily life easier. And especially I want to thank the Celta fans, the same crazy ones who were cheering and supporting the team when we were fighting relegation on the final day four years ago, were the same faces celebrating two consecutive European qualifications."
He closed with a message of gratitude.
"It has been an honour to defend these colours. I leave with my heart full of friendships, memories and experiences that will last a lifetime. Thank you for making me feel like one of the family."
Mingueza leaves Celta having made 147 official appearances, scoring seven goals and providing 15 assists across his four years in Vigo, a spell that also earned him four caps for the Spanish national team.
While one full-back departed, another returned. Javi Galan began pre-season on Tuesday, having signed a two-year contract with Celta last week to rejoin the club he left in 2023.
"Very happy to be back. It's been for several reasons. Seeing from the outside how the club has grown since I left. They've improved a lot in terms of football, the coach's style of play and the good group you can see from outside, which people inside had already told me was even better, and seeing the whole structure of the club," Galan said.
The left-back, who returns to a place where he was happy, is eager to contribute again: "I lived very good years here and I feel it's my home. I've gained more experience. Now I'm a much more complete player than when I left." He also praised the identity Celta have built under head coach Claudio Giraldez. "The identity that the coach and players have managed to give the club. They're in tune with each other, we've also seen that with the reserve team getting promoted to Segunda Division. It's a style of play that runs through the whole club."
Galan admitted he had always relished facing his old side.
"It always excited me a lot, whenever I came back to Vigo to play as an opponent, seeing the city, the stadium, old team-mates. I'm really looking forward to enjoying it now, but this time as a home player. I'm going to give everything, and I'm sure there will be plenty of success. I can't wait to play at Balaidos again as a home player."