The 20-year-old Brazilian was back on action for City in last night's 0-0 derby draw with Manchester United after being sidelined by a broken bone on his foot since mid-February.
Guardiola was thrilled to see Jesus come on late in the contest and admitted he has been delighted by the impact the youngster has made since joining the club from Palmeiras in January.
"We are so happy [Jesus is back]," Guardiola said on Sky Sports. "He has a special talent.
"He created two chances against Tottenham in his first game and did the same today.
"It was a pity he moved beyond the last defender but I will always think what would have happened if Gabriel Jesus would have been with us all season.
"We did not buy another striker because he could not come before January, so we missed four or five months without him. His impact was amazing with the team and everybody.
"With him and Sergio I'm pretty sure the chances we had would have been a little bit different. But it is what it is."