Diego Simeone likes his players to be able to run through brick walls for him.
Saul Niguez was ready to give up a kidney for the cause two years ago, so it's little wonder his coach has always fought off Premier League interest in the 22-year-old who will face Chelsea on Wednesday night.
Fulham wanted Saul when he was 16 and Manchester United wanted him long before he established himself in Atletico's first team but he stayed and even the burst kidney sustained in a Champions League game in 2015 against Bayer Leverkusen has not held him back.