Iniesta was impressive in victory over Viktoria Plzen.
Guardiola said of the 27-year-old World Cup winner: "Andres, when he's in good shape, is unique, a star player. He works hard and scores more goals than you think, and he has this ability to break down defences which is so important for us.
"He's come back really well from his injury. Last year he was vital for us, and now we hope he will be just as important. For our part, we'll try to take care of him and make sure he's okay."