Simeone left out Suarez, Koke, Llorente and Carrasco, with Felix taken off in the second half when they needed an equalizer
La Liga leaders Atletico Madrid crashed out of the Copa del Rey Wednesday after suffering a shock second-round 1-0 defeat by third-division Cornella.
Cornella sit seventh in their Segunda B division, Spain's third tier, but deserved a historic win thanks to a volleyed finish by Adrian Jimenez in the seventh minute.
Atleti's task became tougher when 20-year old Ricard Sanchez was sent off in the 63rd minute, while Saul Niguez had hit the crossbar in the first half.
Diego Simeone also left out some key players including Luis Suarez, Koke, Marcos Llorente and Yannick Carrasco, with Joao Felix taken off in the second half when they needed an equalizer.
But Atletico also struggled for fluency and chances against a far less prestigious opponent.
Cornella had lost to Barcelona's second team in their previous match in December and in a rare appearance in the Copa del Rey's last 32 in 2015 they took a 9-1 drubbing on aggregate by Real Madrid.
Atletico's defeat makes it consecutive seasons they have lost to a third-tier side in the cup after being knocked out by Cultural Leonesa 12 months ago.
Atletico Madrid defender Kieran Trippier’s 10-week suspension for a betting violation has been put on hold by world football governing body Fifa, an Atletico source said Saturday.Sports Tribune on Sunday, 3 January 2021
It also comes as a jolt ahead of two tough games in La Liga against Athletic Bilbao this weekend and then Sevilla, even if one less competition could aid their title challenge in the coming months.
Atletico, who sit two points ahead of Real with two games in hand, could be without Felix against Bilbao after Simeone confirmed he took a knock to his ankle.
Defender Jose Gimenez also went off injured early on and now looks unlikely to feature Saturday.
Jimenez gave Cornella the lead with a hooked finish, connecting brilliantly with Agus Medina's cross at the near post to put his team in front.
Saul struck the crossbar after a weaving run and shot from Angel Correa caused the ball to pop out to the midfielder in the penalty box.
Yet Cornella were never particularly troubled and played the last half an hour with an extra man after Atletico's Sanchez picked up a second yellow card for leaving a foot in on Cornella's goalkeeper Ramon Juan.
Real Betis had earlier beaten UD Mutilvera 3-1 to reach the next round while Levante, Elche and Granada also made it safely through.