Jesus, 29, joined from Arsenal in the summer for a reported €15 million after Barcelona failed to convince Atletico Madrid to sell Julian Alvarez.
The Brazilian has played second fiddle to countryman Raphinha, but has impressed during his limited game time, scoring three goals in five appearances, just one of which has been a start.
With Raphinha currently sidelined with a muscle injury, Jesus is expected to lead the line for Barcelona in their Champions League clash with Galatasaray on Tuesday (October 13).
Speaking to reporters ahead of the game, Flick admitted to being surprised by how well the forward has adjusted to life at Barcelona.
"He's ready. Whether he plays, which we don't know yet, we'll decide after training," said Flick about Jesus.
"We're very happy with him. He's a bit of a surprise, we have to admit. His behaviour is fantastic and he's a great player."