2. Youth or experience?
This season, Diego Simeone has been gradually phasing out the ageing players in the Atleti squad to pave the way for younger, fresher players. Captain Gabi has seen his undisputed starting berth taken by Thomas Partey, while the likes of 21-year old defender Lucas Hernandez and 22-year old Ángel Correa have also come into the side.
Now, in such a big fixture, Simeone needs to decide whether he wants to go with the proven products or keep giving the youngsters a shot. In midfield, Simeone could choose either Thomas or Gabi to accompany Saúl and Koke. Diego Godín seems a certain starter in the middle of the defence and, even though Stefan Savic has usually accompanied him, Lucas is Atleti's most in-form centre-back.
Up top, Fernando Torres is usually reliable when it comes to offering a physical and aerial presence that Antoine Griezmann can play off of. Yet, El Niño's best days are behind him and a more dynamic striker pairing with Correa or Luciano Vietto is capable of troubling Qarabag's rigid defensive structure.