#1 Antoine Griezmann

Arguably, the most dangerous threat to Los Blancos' rearguard will be Antoine Griezmann. He is the leader of Atletico Madrid's attack and Real Madrid will be wary of threat Griezmann possess in the final third.
The Frenchman has scored 10 goals and provided 7 assist in the LaLiga. In just 6 Champions League fixtures, he has scored 4 goals and racked up 2assists, also bragging of 3 Man of the Match awards in the process.
Griezmann has a knack of troubling Real Madrid's defense as his 7 goals against Los Blancos depicts. Sergio Ramos and co. are familiar with the Frenchman's abilities and will look to contain the striker as much as they can.
There is no doubt that he is the most influential attacker in Atletico Madrid's defensive set up, who can change the tie with not only goals but with an effective range of passing in the opponent's half.