Gabriel has struggled for form this season.
But attempting to encourage the youngster, Guardiola said: "Of course he needs a goal, strikers live for that, but his performance against Fulham (in the Carabao Cup on Thursday) was excellent, how he moved, now he created, how he caused problems.
"People don't realise a lot of his movements without the ball. For example, our third goal for Bernardo Silva against Donetsk in the Champions League, Gabriel helps the goal. He is a player who gave us a lot. He is a young player, he can still improve, a little more calm inside the box.
"But he has desire, that is why he accepted a contract for many years. We are going to help him."