Monchi turned down an offer from Arsenal in order to return to Sevilla, he said on Monday, adding that he had not been approached by Real Madrid.
After leaving Roma earlier this month, Monchi had been linked with a move to the Gunners as a replacement for departed head of recruitment Sven Mislintat.
But Sevilla announced his return as their sporting director at the weekend and, speaking at a news conference on Monday, he said: "I thank Arsenal for their interest.
"It has been the club that has shown the most interest in me but, in the end, I evaluated all of the offers I had on the table and I chose the one that convinced me most.
"I had other options, and very important ones that were flashier, but I've chosen Sevilla because its sporting project convinced me.
"I want to thank everyone that contributed to my return to what I consider to be my home."
Monchi, 50, worked with Arsenal coach Unai Emery at Sevilla, with the club winning three consecutive Europa Leagues, and said he wanted to help the La Liga club grow in his second spell.
"Many people outside of Seville have told me that I've made the wrong choice, that sequels are never good," he said.
"I've evaluated all of this. I'm here not because I'm a Sevilla fan, not to save someone's skin, but because in the conversations I've had with the club president and other club executives, they have transmitted to me an idea of what Sevilla's future could be that coincides with what I believe Sevilla's future should be.
"My idea is to help Sevilla grow. I want to build a Sevilla team that can fight among the best."
Sevilla president Jose Castro said: "Monchi is a special person. He has a contract like everyone else at the club, but it's an indefinite one."
Monchi left Roma shortly after the club sacked coach Eusebio Di Francesco following their Champions League exit to FC Porto.
"I wouldn't change the two years I spent at Roma," he said. "I made a rookie mistake which was not to have got to know the club before I signed for them, and I was surprised with what I found.
"I left Roma for a simple reason -- at a certain point, the club wanted to follow a different path to the one I considered we should take and, in the end, we believed it was best to go our separate ways."