"The offer that we proposed did not match their expectations. Sadly, the negotiations are now finished," Boca president Mauricio Macri said on Radio Del Plata.
"Villarreal wanted 17.5 million Euros (£11.8million) and we offered 8.8 million Euros (£5.9million).
"It is a shame as we really wanted him to play for us."
Macri, who is preparing to take over as Buenos Aires mayor, added: "We made the best offer we possibly could.
"No other team in South America can make a similar type of offer but at least we tried it."