Former Real Madrid midfielder Rafael van der Vaart - who retired in November - has been left baffled by Isco's snub.
Real Madrid were beaten by Leganes but still stumbled into the Copa del Rey quarter-finals on Wednesday.
A 1-0 defeat at Leganes did not stop Real Madrid progressing to the Copa del Rey quarter-finals, but Santiago Solari was unimpressed.
After Thierry Henry's side failed to beat 10-man Nice on Wednesday, they have made their worst start at home in Ligue 1.
Valencia have confirmed the club want to end Michy Batshuayi's loan early, with Monaco in talks over a deal for the Chelsea striker.
A brace from Santi Cazorla halted Real Madrid's momentum as Luis Garcia's side claimed a 2-2 draw in the first LaLiga match of 2019.