Speaking before City's final pre-season friendly against Tottenham in Nashville, Guardiola stressed he was "happy" with the strength of his squad.
And when asked about his future plans during this summer's transfer market, and in particular in defence, the Spaniard explained: "I am happy with John Stones, Vincent Kompany and Nicolas Otamendi.
"We don't have too much more to spend. We have spent a lot because we didn't have a lot of guys.
"But if the market gives us a chance we are going to try to sign (a defender)."
City, Sky Bet's 15/8 Premier League favourites, have already spent over £200m during pre-season and Guardiola is generally satisfied with his haul, adding: "I'm happy with the squad we have.
"I was happy with the players I had last season. You never hear one bad word about the players.
"But we'll buy players to reinforce the team, like other teams around the world, until August 31st.
"But if not we'll go with what we have. The market is so expensive."
As for the forthcoming season, he added: "Expectations are high to win titles. We didn't get it last season.
"But it's not about the tactics - whether you play three, four, five-man defence - it's about believing you can do it.
"We believe in the principles, whether it be high pressing, aggressive in some areas with the ball or without the ball, it's about reinforcing the principle of what we have to do."
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