Summer returnee Mariano could make his second Real Madrid debut after he was named in the squad to play at Athletic Bilbao on Saturday night (22:45 UAE).
Mariano, 25, was bought back from Lyon last month for €22 million after 14 months away. He previously scored once in eight La Liga appearances in 2016/17.
The striker is likely to be an option off the bench for head coach Julen Lopetegui. He was an unused substitute in the 4-1 victory against Leganes prior to the international break.
Elsewhere, right-back Alvaro Odriozola could make his bow as a replacement for right-back Dani Carvajal after his exploits for Spain. The €30m buy from Real Sociedad in July has been waylaid by a groin injury.
Madrid have won all three of their 2018/19 La Liga fixtures.