And he praised youngster Rico Lewis for helping to alter the dynamic of the match as we secured a crucial three points to maintain the pressure on Barclays Premier League leaders Arsenal.
With the game goalless at half-time, the City boss made a double change during the break with Lewis and Manuel Akanji replacing Joao Cancelo and Kyle Walker.
The City boss then made another double switch on the hour with Jack Grealish and Riyad Mahrez coming on and immediately combining for the matchwinner.
After consulting with coaches Rodolfo Borrell and Enzo Maresca, Guardiola said he felt to need to make early substitutions to change the momentum of the game.
“All the managers try to make decisions to help the team – sometimes you are losing but the team is playing good and why I should change when I have the feeling they are doing well?” the boss said in his post-match press conference.
“Today, after 20 minutes, because you have to give them a little bit of time to try, I decided I didn’t like what I was seeing. So why wait?
“So I spoke with Rodolfo and Enzo, and we said: ‘okay, we have to change something otherwise it would have been more difficult.
“Everyone could see from the first minute of the second half, it was a different Man City.
“And this dynamic from Rico helped everyone to have their freedom. He changed the game from minute one.”
Rodri and Joao Cancelo started the match in unorthodox positions and Guardiola felt his side were more effective when they switched to a more familiar set-up.
“I want to say thank you to Joao and Rodri for making the effort to play in those roles, but I imagined that type of game where they might have had five at the back, which they sometimes play, we could use Kyle [Walker] and Joao as full-backs,” he said.
“But in the first half, everything was sloppy, and we couldn’t keep contact with the wingers or the attacking midfielders and we didn’t create much. Our pressing was so poor, and we were not well organised.
“In the second half, especially with Manu and Rico – and this young boy has the quality to make us better.
“Everyone can play better, but when [Rico] came in, Rodri played better, Kevin [De Bruyne] played better, and he has the talent to do this.
“Since we have come back, he has been playing for us and he has become fundamental for us, the way he is playing right now.”
