Fernando Signorini, Argentina's physical coach, explained it in a book
Two of the best players in history, Diego Maradona and Lionel Messi rarely coincided. Maradona was only Argentina coach from 2008 to 2010 but this period was enough to leave very interesting anecdotes.
The last one has been revealed by Fernando Signorini, physical coach when Maradona was in the albiceleste, in a book called Fútbol llamado a la rebelión (Football caller to the rebellion). Signorini recalled a curious anecdote between Messi and Maradona held during a training a day before a friendly match:
"We went to France to play a friendly vs a local team in Marseille. The day before we trained in the stadium and Diego worked with the XI men that would play.
At the end, Mascherano, Tévez and Messi asked him to stay and practice free kicks, and Maradona accepted. Then Messi kicked the ball and it went far away from the goal.
He did a gesture of annoyance and while he was going to the dressing room I told him:
-Tell me: will you go home with this shit? Stop regreting. Take the ball and try it again.
I ended saying this and Diego, who had heard it all, approached Messi and told him:
-Leíto, Leíto, come, papá. Let's to it again.
It was like a teacher with his pupil. And he followed:
-Put the ball here and listen to me: don't kick it too fast, because then it doesn't know where it has to go.
Then, he caressed it with his left foot, kicked and it went straight to the angle of the goal, in front of Messi 's admiration."