Iker Muniain and Mikel San Jose have both reportedly begun contract talks with Athletic Bilbao.
Muniain, 21, and San Jose, 24, both see their contracts with the Basque outfit expire next summer, with a host of European clubs believed to be monitoring proceedings.
The pair have been key performers in a season that has seen Bilbao finish fourth in La Liga behind Atletico Madrid, Barcelona and Real Madrid.
According to reports in Spain, negotiations have begun with both parties and it is understood that there are no real obstacles in either situation.
Bilbao's season draws to a close this evening with a trip to Almeria.