The targetman is a firm favourite among the Leonesfaithful after playing 298 games and scoring 110 goals since breaking into the side in 2005. Last season, he played a key role in helping Marcelo Bielsa's side to the Europa League and Copa del Rey finals.
|2011-12 GOAL.COM 50 WINNER:
|The Portuguese superstar has topped our definitive countdown of the finest players from 2011-12. Click here to view our slideshow from 50-1!|
The 27-year-old's current contract runs out on June 30 2013, and Athletic have been seeking to tie him down to a long-term deal.
But he has turned down a reported €4.5m-per-season deal at San Mames, largely due to his desire to play in the Champions League and challenge for major honours, according to the reports.
The news is a big blow for Athletic, who must now decide whether to sell their main asset now, or let him leave on a free next summer.
Real Madrid and Barcelona have been credited with an interest in the player recently, and ETB have disclosed that Bianconeri are also courting the forward, after missing out on Napoli forward Edinson Cavani.
Athletic travel to Slaven Koprivnica for the second leg of their Europa League qualifying tie this Thursday, which they lead 3-1.