Calero, born in Valladolid, joined Espanyol in the summer of 2019 and made 181 official appearances across his time at the club — including two seasons in the Segunda División and a Europa League campaign in his debut year. He scored five goals from the heart of defence.
The club's farewell was warm.
"Fernando Calero always showed signs of his professionalism and adapted from day one to his new club. RCD Espanyol would like to publicly thank him for his commitment, dedication and effort from day one and wishes him good luck in the new professional stage he can undertake."
Four loan players also departed in the same announcement. Left-back Carlos Romero and midfielder Ramón Terrats return to Villarreal — Romero having signed a new deal at the Yellow Submarine until 2031, where he will now join the first team. Romero started 36 league matches and Terrats 31. Both said their goodbyes to supporters earlier in the week through social media.
Congolese midfielder Charlie Pickel returns to Cremonese, having played six matches in all competitions. Belgian winger Cyril Ngonge, on loan from Napoli and used in nine games, also departs. Espanyol thanked all four for their "professionalism, commitment and effort."
The departures arrive as coach González spoke publicly about the season just ended — and what comes next. His contract renewal was automatic upon securing La Liga survival, and he expressed clear enthusiasm for the new working relationship with Monchi.
"I'm happy because the season ended well," he said. "The team consolidates in the top flight for another year, which is how you can grow. I'm happy to continue, with a renewal that was automatic following survival, and with the confidence of both the president and the sporting director, Monchi."
He graded the campaign with characteristic honesty: "I'd give the season a seven. If they'd told us at the start that we'd finish as we did, we'd all have signed that. After the first half of the season it feels like a little less, but we've had a better year than last year and we overcame a complicated situation."
On the second-half collapse, he pointed to psychology rather than tactics.
"A lot of anxiety. You analyse everything and you don't really understand the reason. Sometimes it's as simple as winning one game. It was a mental block, and winning against Athletic Club changed things. Between everyone we managed to pull through. I see the club increasingly united."
González was equally direct about ambition: "We are a sleeping giant and we must try to always be better, working and doing things right, everyone together. That excites me greatly and I think we have room to grow."
The summer workload, he said, is already underway.
"There is a lot of work ahead. We need to be in sync with Monchi — to bring in players that we both want and move in the same direction. We need to find players who help take the team a step further and allow us to develop a style of play that is different and closer to what we want, which until now we have not been able to achieve."
Monchi, the experienced sporting director who built Sevilla into a European trophy machine before spells at Roma and Aston Villa, arrived at Espanyol last month. His first full window with González at his side will define whether the sleeping giant stirs.