Pogba was jeered by a section of home fans in the second half of the friendly in Nice after a misplaced pass, and again when he was replaced by Steven N'Zonzi late on.
Griezmann, who was among the scorers on the night, admitted that whistles are part and parcel of football, but insisted that France are a united outfit and have complete faith in what Pogba offers to the team.
"The whistles are part of football, you have to stay tough mentally," the Atletico Madrid forward told TF1.
"We're all playing for the same shirt. He plays his game, you're used to him scoring. We don't expect that from him, only that he rotates the ball and plays for the team.
"He has had a difficult season at Manchester United but he has a lot of confidence in himself."
Pogba, once the world-record signing, has won 53 caps for France and will be heading to the World Cup with Les Bleus.