Sevilla warned clubs targeting midfielder Steven N'Zonzi that they "do not sell cheap" as they announced the signing of left-back Guilherme Arana from Corinthians.
Arana, 20, who won two league titles with Corinthians, has signed a contract until 2022, a club statement said.
He moves to Sevilla for a reported fee of €11 million, and Sevilla president Jose Castro told Onda Cero radio: "Arana was our first option and we've worked hard to get him for a fee in accordance with what we could afford.
"We tried to sign him in the summer but the fee was prohibitive as Corinthians didn't want to let him go as they wanted to win the title."
Castro said former Blackburn and Stoke midfielder N'Zonzi, a reported Arsenal target, has a €40m release clause in his contract.
He has not played for Sevilla since Nov. 21 after a reported row with coach Eduardo Berizzo and said this week he wanted to leave in the winter window.
But Castro said the club had not received any offers for the 28-year-old and added: "He has two-and-a-half years left on his contract and a €40m clause.
"He is one of the highest paid in the team, and we don't sell cheap."
Castro said he hoped N'Zonzi's situation could be resolved and added: "It's a technical decision [that he is not currently involved].
"They are not counting on him and we have to respect the work of the coaches, who win games with and without N'Zonzi.
"They have said that it's not an irreversible decision. We hope."
Arana's arrival, meanwhile, means Sevilla will need to vacate one of their non-European player slots, currently occupied by Luis Muriel, Paulo Ganso and Montoya.
Montoya has started just five games in all competitions since joining from Rosario Central in January and is the leading candidate to leave in January, Castro said.
The president also voiced his support for Berizzo, who is recovering after prostate cancer surgery.
He said: "I speak to him every day and I go and see him. He is improving day by day.
"He was very happy today [Thursday] because he felt no pain. The most important thing is that he takes care of himself but I see him well."