The Reds head into the match on the back of an impressive 1-0 victory against LaLiga giants Real Madrid in the UEFA Champions League on Tuesday.
"I think the game against Madrid really helps to get in the right energy and on the same level it will be on Sunday," said Wirtz to Liverpoolfc.com.
"I think it was a good test and we are ready to compete again. I spoke of course to my teammates, and they told me that it will be a tough game because they [City] keep the ball a lot and you have to run a lot."
Man City will also be confident heading into this encounter after dominating in their 4-1 win against Borussia Dortmund on Wednesday, scoring three or more goals for the third consecutive fixture.
"I think they are in a good moment and we are back also, and I think it will be a good game. We have to use our chances and to have a good plan for the game," added the Germany international.
"We are really happy that we could win two times now and hopefully another time on the weekend, then going with a good feeling into the international break."
Wirtz has made 15 appearances for the Reds under Arne Slot since joining the club from Bayer Leverkusen in the summer and has contributed with three assists.
Liverpool will also be looking to win their third consecutive league fixture against the Cityzens.
Manchester City secured a second successive Premier League victory at home against Sunderland, Chelsea were held scoreless away to Bournemouth while Tottenham managed to beat Brentford.
Aston Villa delivered a major jolt to the Premier League title race as Emiliano Buendía struck deep into stoppage time to seal a 2-1 win over Arsenal on Saturday.
David Moyes urged Everton to stay on the front foot as they prepare for Saturday's Premier League meeting with Nottingham Forest at Hill Dickinson Stadium, where Sean Dyche made his first return since leaving the club nearly a year ago.
Mikel Arteta has said that Aston Villa's blistering run of form has made them genuine contenders in the Premier League title race, as Arsenal prepare for a high-stakes trip to Villa Park.
