Arsenal have reached the "basis" of an agreement to sign Villarreal defender Gabriel Paulista with Costa Rica winger Joel Campbell going the other way on loan, the Spanish club’s Twitter feed said on Saturday.
Brazilian Gabriel said goodbye to Villarreal fans ahead of their La Liga clash with Levante on Saturday.
"There is the basis of an agreement with Arsenal for Gabriel," read the message on Twitter.
"Welcome Joel Campbell, loan agreement with Arsenal until the end of the season."
Media reports have said the fee for the 24-year-old is in the region of 20 million euros ($22.4 million), which is his buy-out clause.
Gabriel signed for Villarreal at the beginning of last season from Brazilian club Esporte Clube Vitoria for a figure of around three million euros and although he struggled during his first year in La Liga, he has matured into a cultured centre half.
Campbell, 22, impressed on loan at Olympiakos in Greece last term and at the World Cup but has barely got a look in at Arsenal.