The striker moved to Mestalla on loan in January and the club have now confirmed their plans to make the deal permanent
Simone Zaza is set to join Valencia from Juventus on a four-year deal for a reported €16 million fee.
'I wouldn't sign Messi for free'
Valencia's sporting director Jose Ramon Alesanco confirmed on Wednesday the club's intent to sign the striker on a permanent deal.
The Italy international joined on a loan deal until the end of the season in January, having struggled to settle during a spell in the Premier League with West Ham.