Messi is not usually taken off by Barca coaching staff.
But Martino explained: "We've talked to Messi from the beginning. The season is long and this way he can rest if he doesn't play every minute in a couple of matches. We came to an agreement quickly.
"Agreeing on substitutions beforehand is a complicated matter. No one would ever take Messi out of a match if the teams are evenly matched. But it can be done in matches where we take a big advantage, this way he can preserve his fitness."
When asked about Messi's pressure on Levante's back line, Martino said, "When Messi starts the pressure, our opponents see that he's trying to win possession back. Hopefully he can do this on a regular basis and that his team-mates follow him."
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