Several key players from both Real Madrid and Atlético Madrid are at risk of suspension for the return leg of their UEFA Champions League Round of 16 derby. Within Real Madrid, Antonio Rüdiger, Eduardo Camavinga, Luka Modrić, Endrick, and Aurélien Tchouaméni are currently carrying two yellow card cautions. Similarly, for Atlético Madrid, José María Giménez and Ángel Correa are also under warning for accumulated bookings.

Zirkzee has issued an apology to Manchester United supporters following his unsuccessful penalty attempt. 

These cautions stem from prior matches in the competition. Real Madrid has participated in ten games to date, including a play-off tie against Manchester City. Atlético Madrid has played eight matches, having directly qualified for the Round of 16 due to their fifth-place ranking in the initial phase of the league table.

Should any of these seven players receive a yellow card from French referee Clement Turpin during the first leg match at the Santiago Bernabeu on Tuesday, they will incur an automatic suspension, rendering them ineligible for the subsequent return leg at the Estadio Metropolitano on Wednesday of the following week.

José Mourinho has initiated legal proceedings against Galatasaray Sports Club. 

Furthermore, the risk of suspension extends to coaching staff. Real Madrid's head coach, Carlo Ancelotti, is also under caution and faces the possibility of missing the return leg if he receives a yellow card. In contrast, Diego Simeone, the Atlético Madrid manager, has received only one booking thus far in the competition, which occurred during their 3-1 defeat to Lille at the Metropolitano Stadium on matchday three.