Manchester City boss reportedly lost his temper with one of the senior members of his squad.
Guardiola reportedly laid into his countryman, midfielder David Silva.
The manager is said to have accused Silva of not running enough in their recent home defeat to Wolves in the Premier League.
It is a result that puts two-time reigning Premier League champions City eight points behind Liverpool.
Guardiola has reportedly tried to remain calm throughout the season, as he does not want to add further anxiety to the City squad.
But he laid into Silva after the Wolves game, per the Daily Mail. He allegedly told the midfielder: "David, you didn't give us enough running. Where were the legs?"
Silva is in his last season at the club and is seen as one of City's greatest ever players.