Croatia were fully deserved winners in Nizhny Novgorod but they were gifted their opening goal following one of the worst mistakes in World Cup history.
Caballero simply had to play the ball up the pitch following Gabriel Mercados back-pass but instead the Argentina goalkeeper attempted an elaborate chip back to his teammate who had pulled out wide.
The pass fell directly into the path of Ante Rebic and the Croatia winger executed a stunning finish to punish Caballeros error.
As Croatias players celebrated, Messi cut an isolated figure near the halfway line and could be seen with his head in his hands.
Luka Modric added a superb second with 10 minutes remaining before Ivan Rakitic added insult to injury by scoring Croatias third of the evening.
I feel sorry for Willy Caballero – I spent three years with him at Manchester City, ex-Argentina defender Pablo Zabaleta told the BBC.
It was a great chance for him at the World Cup with Sergio Romeros injury – he could have came in and showed his class.
But you cannot make those errors at a World Cup. I feel so sorry for him – but it was a huge mistake.
Argentina must now beat Nigeria in their final group game to stand any chance of progressing to the last-16 stage.
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