Pogba has struggled for consistency at United but the star midfielder played a key role in France's World Cup triumph in Russia.
Pogba's performances came after a difficult campaign in Manchester, where he was benched for both legs of United's Champions League last-16 defeat to Sevilla, while he was substituted in Premier League losses against Tottenham and Newcastle United.
That sparked speculation over his United future amid claims of a falling out with manager Mourinho, who has suggested the former Juve player can lose his focus at the Theatre of Dreams.
"I don't think it's about us getting the best out of him, it's about him giving the best he has to give," Mourinho told ESPN FC.
"I think the World Cup is the perfect habitat for a player like him to give [their] best.
"Why? Because it's closed for a month, where he can only think about football. Where he's with his team on the training camp, completely isolated from the external world, where they focus just on football, where the dimensions of the game can only motivate.
"During a season, you can have a big match then a smaller match, then one even smaller, then you can lose your focus, you can lose your concentration, then comes a big match again.
"In the World Cup, the direction of the emotion, of the responsibility, of the big decisions is always growing up.
"You are in the group phase, you go to the last 16, to the quarter-finals, to the semi-finals, to the finals. This feeds the motivation. This feeds the concentration of a player.
"So I think it was the perfect environment for him."
Pogba scored six goals and tallied 10 assists as United finished second in the Premier League last season.