"You never know. It's like a watermelon. You have to open to see if it's good or not. The prospect was good. Jesus is a fighter with instinct for the goal," Guardiola told British media.
"He has dreams about what he wants to do in his future career. He wants to become something in world football, and we're going to try to get it for us."
Jesus' rise might have come at a cost for Sergio Aguero, who was benched on Wednesday despite being fit, but Guardiola said the explosive Argentine striker remained firmly part of his plans.
"Aguero is so important for us. He knows and everyone knows we cannot succeed without his contributions," Guardiola added.
"I sit with my staff and we take the decisions, and it depends on the performance of the past. In this crazy calendar it is impossible to play with the same players all the time."
City, who are fifth in the league after 23 games, 10 points behind leaders Chelsea, host relegation-threatened Swansea City, in 17th, on Sunday.
(Reporting by Shravanth Vijayakumar in Bengaluru; editing by John Stonestreet)