Lionel Messi has revealed that it is best to avoid conversing with Barcelona and Argentina teammate Javier Mascherano on certain days.

Mascherano has published a book, co-authored with Nicolas Miguelez, entitled The 15 Steps of Leadership, in which he talks about his career and motivations.

The book's preface was penned by four-time Ballon d'Or winner Messi, who opened up about the intensity of his club colleague and compatriot.

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"He has his days. Sometimes he comes in wanting to talk and make jokes, but he also has crazy days," Messi wrote.

"When that's the case it's better not to talk to him. We see him there and no one dares to say anything."

The 28-year-old was absent for Argentina's 2-0 defeat at home to Ecuador in the side's first qualification fixture for World Cup 2018 due to injury.

In his stead, Mascherano took the captain's armband, and Messi admitted that he often relies on the help of his teammate to orchestrate the side.

"Masche knows how to handle each situation. He is a very positive leader," he added.

"At the World Cup in Brazil I had the armband, but he was by my side the whole time, fixing each error."

Argentina will look to bounce back from its opening loss when the team travels to face Paraguay on Tuesday.

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