Arsenal sent a representative to Valencia on Tuesday to discuss the signing of goalkeeper Vicente Guaita for a fee of around £17 million.
Valencia had planned to keep Guaita, but the shot-stopper was furious at being left on the bench for the weekend win over Malaga (when coach Miroslav Djukic picked Brazilian Diego Alves instead) despite claiming only last week that he would fight for his first-team future at Mestalla.
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The 26-year-old met with his representatives after he was left out by Djukic on Saturday, when Valencia beat Malaga 1-0, and Arsenal appear to have moved quickly for the highly-rated goalkeeper.
Chief negotiator Dick Law travelled to Spain on Tuesday evening to discuss terms with Valencia president Amadeo Salva and, although an agreement has not yet been reached, further talks are expected on Wednesday.
Earlier in the day, Salva claimed Guaita would only be allowed to leave if he requested a transfer.
"It will have to be he who says he doesn't want to stay at Valencia [because] we don't want to sell him and we will protect the interests of our club," he said.
"If he wants to leave, he will have to say so. We want him to renew his contract, but it is up to him whether he accepts or rejects our offer. Nobody has told me anything about Arsenal, but if anyone wants to sign him his clause is €30m (£25.5m)."
However, it is believed Valencia will sell for considerably less than that figure, with the Costa Blanca club also now having retracted their offer of a new contract.
Meanwhile, Spanish station Cadena Ser reported on Tuesday that the goalkeeper has already said goodbye to his team-mates.
If the move goes through, Guaita will be the second star to leave his local club this summer for north London after Roberto Soldado joined Tottenham earlier in August.
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