After just four NRL games, the Wests Tigers junior has been drafted in to Brad Fittler's side to play fullback in place of the injured Jarryd Hayne.
"It was very surprising when I got the call up," said Tedesco.
"Simon Dwyer called me and I thought some of the boys were stitching me up.
"I'm very excited to get in the camp now.
"It's just sinking in and I'm going to be ready for Sunday."
Tedesco is hoping his first rep camp will serve to lift his game when he returns to Wests Tigers to take on Brisbane Broncos at Campbelltown Stadium in Round 7.
"I think it will definitely improve it," said Tedesco.
"Playing with some quality players in this squad will help my game.
"I'm hoping I can bring the experience back and hopefully play some good footy for the Wests Tigers.
"I'm going to be pretty honoured playing fullback for City."