Simeone's sensational tirade, reported to be an audio message sent on mobile platform WhatsApp to Atletico assistant coach German 'Mono' Burgos, emerged hours after Argentina's heaviest defeat in a World Cup group stage since 1958.
Simeone's press spokesman and Atletico's head of communications did not respond to requests from Reuters asking to verify the audio.
"What's happening to the team right now is what has happened to Argentina in these last four disgraceful years: anarchy, no leadership from the players, coaches or directors. The team is lost," former Argentina international Simeone can be heard saying.
"Right now in the dressing room they are coming to blows. Someone needs to stand up and fight."
Simeone also appeared to call into question the true quality of Argentina's usual talisman Lionel Messi, who has had a minimal impact at tournament in Russia and missed a penalty against Iceland in the Group D opener, while his rival Cristiano Ronaldo has scored four times for Portugal.
"Messi is very good but he is very good because he is accompanied by extraordinary footballers. If you have to choose between Messi and Ronaldo in a normal game, who would you choose?" said Simeone.
The Atletico coach appears to be talking to his assistant Burgos, a former goalkeeper, when he criticises Argentina keeper Willy Caballero for gifting the opening goal in the game to Croatia winger Ante Rebic.
Simeone said: "The goalkeeper has done this before hasn't he German, he did it against Spain, against Italy when they hit the post, and if you slip up like that in a World Cup, it's a goal."
(Reporting by Richard Martin; Editing by Christian Radnedge)
