The 31-year-old centre-back made his comeback from a hamstring strain against Roberto Mancini's side after two weeks on the sidelines and, following hard work on the training ground during the international break, he is raring to go ahead of the Tyne-Wear derby.
"This is a good opportunity for me, it's a derby game," Cuellar told the Sunderland Echo.
"The City game was the first one I played after my injury but now I've had a bit more time to prepare and I feel great.
|16/1||Carlos Cuellar is 16/1 with William Hill to score anytime in Sunderland v Newcastle
"We have already showed how good we are defensively and how good we are attacking. We've had the opportunity to have a break, to relax and prepare for the game on Sunday."
Defeat against the Premier League champions saw Sunderland's unbeaten start brought to a halt but the Spanish defender is confident that Martin O'Neill's side can bounce back with a win at the Stadium of Light on Sunday.
"You have to learn from your mistakes but in Spain we say you cannot take your skin off just because you make a mistake or lose a game," he added.
"I think the confidence in the team is very high.
"When you lose everyone is unhappy, but if you look at the table and you look at the games we have played before that, you don't have to be scared or lose any confidence because I think the team is doing very well."