Fernando Llorente off Athletic roster
The pair was left out of the 5-3 Spanish league loss to Real Betis and will also miss Thursday's first leg against HJK Helsinki.
Martinez, a defender or midfielder, has been linked with a move to Bayern Munich. Llorente told the club he would not renew his contract, which runs to the end of this season, with several European teams eyeing the powerful striker.
Last season, Bilbao reached the Europa League and Copa del Rey finals.
Bilbao coach Marcelo Bielsa says "with those left we'll try to achieve something like we did last season."