Arsenal manager Arsene Wenger expressed cautious optimism over his side's move for Villarreal's Brazilian centre-back Gabriel Paulista on Thursday, describing the transfer as "50-50".

Gabriel, 24, reportedly has a release clause of 20 million euros ($23.3 million) in his contract, but British press reports claim Arsenal have offered a fee rising to around 13 million euros.

Any deal would also be contingent on the player being granted a work permit by the British government. Gabriel does not meet the automatic requirements because he is not yet a full international.

"We are talking at the moment. Can we find an agreement or not? I don't know. We are slowly progressing, but there is a chance," Wenger told a press conference on Thursday.

Asked about the chances of a deal going through, Wenger replied: "50-50 at this moment, yes.

"We are ready to pay the price we think is right for a good player, no matter what the price is. If we think it's the right price, we will pay."

Non-European Union players wishing to play in the Premier League must play for a country ranked within the world's top 70 and have played in at least 75 percent of their country's competitive games over a two-year period if they are to be automatically granted a work permit.

But clubs can argue that a player with "exceptional target" should be granted an exemption, as Arsenal have previously done with Japanese midfielder Ryo Miyaichi and Brazil-born Croatia striker Eduardo da Silva.

"If a player we want needs a work permit then we will defend it now because we will not necessarily want to do it in the summer," added Wenger.

"We respect the rules in England. When you buy a player who does not fulfil the criteria and needs a work permit, you go in front of a commission and they tell you yes or no. We will accept that."