When Atletico Madrid last travelled to Germany to face Bayer Leverkusen for a Champions League knockout tie, Saul was enjoying a breakthrough moment in his career before being struck down by a traumatic injury.
Kyriakos Papadopoulos challenged the midfielder for a high ball and dealt a fierce blow that smacked a kidney, eventually forcing Raul Garcia to replace Saul after futile attempts to continue.
Before arriving in the dressing room, the Spaniard became dizzy, vomited several times, and experienced convulsions.
The Atletico medical team took the decision to move Saul to hospital, where he became frightened by a lack of feeling in his arms and legs, staying in the unit for four days.
Saul was accompanied by his father and Rojiblancos medical head Dr. Villalon throughout his stay, finally allowed to leave once the affected kidney had drained.
Physically sound, the midfielder was straight into the action upon his return to training but the mental effect was clear for all to see, as the player got a tattoo on his wrist that was inspired by the events in Leverkusen.
It would take several weeks for Saul to be allowed to play after that night, and it's one that will no doubt be on his mind as Atletico face Bayer in the last-16 on Tuesday.
