Pique admitted Messi is a player who can "change everything" after he stepped off the bench to help Barcelona reach the Champions League semi-finals.
Central defender Pique told Sky Sports: "We are talking about the best player in the world. It doesn't matter if he is a little bit injured, he can change everything and he did again.
"We are really lucky and really proud to have Leo on the team and we have to use him when we are struggling a little bit.
"We knew that for us to have Leo on the pitch was really important. He is our reference, he can score he can pass, he can do everything and he helps us a lot.
"If you have him you have to use him and try to use the best part of him and he helped us a lot."