Eibar want West Ham youngster Reece Oxford – potentially on a permanent basis.
The Spanish club have made an enquiry about the 19-year-old ahead of a potential loan move.
The transfer window in England is closed but remains open elsewhere in Europe, meaning Premier League players can still be sold or loaned to clubs on the Continent until the end of the month.
Dutch outfit AZ Alkmaar have also shown some interest in Oxford, who impressed while on loan at German club Borussia Monchengladbach last season.
Both Alkmaar and Eibar are interested in a loan deal with a view to an eventual permanent move for around £2m.
There has been speculation about Oxford’s future for some time and a number of clubs have made enquiries about him.
But West Ham boss Manuel Pellegrini, speaking at a press conference earlier this month, appeared to suggest the player would not be going out on loan again this summer.
Pellegrini said: “We bought those new nine players, some players like Fernandes and Martinez need to play and they knew from the beginning that they were going out on loan so the squad is the squad that I want for this season.
“I don’t think that we are going to have any other player going out for the moment.”