The 19-year-old signed for the club in the summer but remained at Palmeiras for the remainder of the Brazilian league season.
His move was ratified by the Football Association earlier this week meaning he is now clear to play – and Guardiola says he comes straight into contention for selection this weekend.
“He is fit, he is ready to be involved in the squad,” Guardiola said. “He is going to help us in the Premier League.”
Jesus is widely considered to be the finest young talent to emerge from South America since Neymar.
His 12 league goals last season were key to Palmeiras winning their first league title since 1994 and since being drafted into the Brazil national side, he has scored five in six and helped propel them to the top of their World Cup qualifying group.
Guardiola says he is excited by the impact he can have on the squad but admits it would have been easier for him to make the transition had he arrived in the summer rather than midway through the campaign.
“He is a young player, 19, so we cannot think he will solve our problems.”he said. “He will have all the time to get involved.
“It will be easier if he could have arrived at the beginning of the season. Now is the middle of the season with not too many training sessions. But he is smart and has quality and is going to help us.
“All the strikers try to help us and Gabriel is going to as well. He is going to be involved in the way we want to play. He is going to help us because he is young, have patience, he wants to create his career here and we are going to help him.”
