Besiktas

Form so far: This is the first time the Turkish side has advanced to the knockout rounds of the Champions League and they will be out there to make the most of it. They haven’t lost a match in the group stage, becoming the first Turkish club to advance to the group stage undefeated. However, they currently sit in the 5th place in the Turkish League.
Tolga Zengin .. I mean Tol-Gea Zengin made more saves than any other keeper in Champions League this season (10) & the highest for Turkish keepers period...
— Turkish Football (@Turkish_Futbol1) December 6, 2017
Oh and he's Beşiktaş's 2nd choice keeper
De Gea who? pic.twitter.com/ksdQfUnpKC
What to what out for: Their discipline and their home fans. Besiktas have played with remarkable efficiency this season, making the most of what they have. And their fans are always there as the 12th man. Pepe’s homecoming to Madrid will also be interesting and can evoke mixed emotions.
Verdict: If we thought that Vicente Calderon or Sevilla Ultras give Los Blancos a hellish time away from home, Turkish fans are in a league of their own. The atmosphere will be beyond intense, but nothing that a club of Madrid’s stature and experience can’t handle.