Messi, 30, agreed fresh terms last week to extend his contract with the Catalan club until 2021, amidst a separate report in Spain claiming that City tried to lure the Argentinian to England with the €100m fee plus a €50m a-year salary.
When asked about the reputed offer, Guardiola summarily denied the rumours.
“It’s not true. Lionel Messi has signed a contract one week ago,” he said. “This was never going to happen; Messi started his career there and he’s going to finish it there. If he wanted to leave he wouldn’t have signed the contract.”
City will be playing against Shakhtar Donetsk in Kharkiv on Wednesday night in the final round of Champions League group fixtures although the Blues are already through as group winners. If they win Guardiola will be the club’s first manager to win all six group games.
“We are doing well but that doesn’t mean you will achieve the title,” he said. “In this competition one bad 45 minutes and you are out. That means you can win the title but go out if you are doing well. I’m not concerned if we are playing the best football.”
Guardiola also has an eye on Sunday’s showdown against Premier League and City rivals Manchester United, with team playmaker David Silva becoming a doubt through injury.
“David had a little bit of a problem in the last minutes [against West Ham United on Sunday],” he said. “We made a test after the game and I don’t know if he is able to play on Sunday so that’s why he stayed there, to recover in Manchester.”