The Spain international has underlined the prolific forward's importance to the Blaugrana and feels they deserved to qualify for the final four in Europe this campaign
The Argentina international started Wednesday's second-leg at Camp Nou from the bench after he picked up a knock in the 2-2 first-leg draw, yet was forced to come on around the hour mark with Barca trailing 1-0.
The Catalans then went on to equalise inspired by Messi and eventually progressed to the next round on the away-goals rule.
"With Messi, we're talking about the best player in the world. It doesn't matter if he's a little bit injured, he can still change everything," Pique told the official Uefa website.
"We knew that having him on the pitch would be important. He's our reference. He can pass, he can score goals; he can do everything. He helps us a lot."
Pique then went on to stress that the Blaugrana fully deserved to qualify for the semi-finals of the European elite this season.
"This club has shown a lot of quality in the last few years. We deserve to be in the semi-finals again," he added.
"In the first leg they scored in the last minute; we deserved a little more. We are happy to qualify for the semi-finals."
The draw for the final four takes place in Nyon on Friday.