The Parkhead club has been repeatedly frustrated in its bids to sign the forward from the recently relegated La Liga outfit.
And it had looked as though Mexican club Monarcas Morelia had won the race to capture the 22-year-old Ecuador international.
However, the player wants to stay in Europe and if the Hoops can match the fee Morelia are willing to pay they can secure his services.
Elsewhere, Celtic have been linked with a bid to land Georgios Samaras' Greek international team-mate Michalis Sifakis this summer.
Sifakis kept a clean sheet as the Greeks stunned football by dumping highly-fancied Russia out of Euro 2012 on Saturday night.
Hoops boss Neil Lennon is still not sure if Fraser Forster, who has spent the last two seasons on loan in Glasgow, will complete a permanent £2m transfer this summer.
And the Scottish champions could snap up Aris ace Sifakis, who has been told great things about Celtic by Samaras, for nothing.
Meanwhile, Rubin Kazan have dismissed reports they have had a £6m bid for South Korean midfielder Ki Sung Yeung turned down by Celtic.
A spokesman for the Russian club said: "This has nothing to do with reality. They want to make the price for the player more expensive."
Elsewhere, Victor Wanyama has refused to pledge his future to Celtic after being ltalking up a move to the Premier League.
Wanyama has been linked with Liverpool, Swansea City, Stoke, QPR, Newcastle and West Ham as well as outfits in France and Italy after an excellent first season at Parkhead.
Asked if he was going to stay with Celtic, Wanyama said: "My concentration now is with Kenya as we have a tough World Cup qualifier against Togo.
"At this point I don't have any comment on the many bids. All I am looking forward to is helping Team Kenya win against Togo."
Wanyama was a key player as the Hoops romped to the SPL title, starting 24 league games for Neil Lennon's side.
The boss will be desperate to keep the 20-year-old, but the former Germinal Beerschot ace has failed to quash transfer rumours on his future.