The Spain international feels the prolific attacker was again impressive, and was surprised with his side's relatively easy win over Spartak Moscow
The Argentina international helped the Blaugrana seal top spot in Group G, and seal qualification to the knockout stages, and Pique was impressed with the forward's impressive showing.
"Messi was fantastic, like he always is. I think he is the best player in the world," the defender was quoted as saying on the Uefa website.
"When you have this type of player you have to use him and this is what we do. We play for him because he knows how to score and how to play and how to win and today it was the same."
The Catalan club struggled in the home match against Spartak, but cruised to a comfortable away win on Tuesday, much to the surprise of Pique.
"I didn't think it would be as easy as it was, but we played a really good game. We were lucky that we managed to score three goals in the first-half and we controlled the game quite easily.
"But there's no denying that they are a really good team, because at Camp Nou they had us in a bit of trouble."
Barcelona resume La Liga action on Sunday when they travel to Levante.