Messi, 30, has maintained his world-class level of performances this season and is currently joint-leader for the European Golden Shoe with 24 league goals in LaLiga.
And Guardiola, who coached the Argentina international during his four-year stint as head coach of the Blaugrana says he is able to improve everyone around him, not just his teammates.
Since Guardiola's departure, the five-time Balon d'Or winner has played under the late Tito Vilanova, Gerardo Martino, Luis Enrique and now Ernesto Valverde.
"I have the perception that [Messi] has improved every coach who has managed him," Guardiola told Directv Sport. "He has the ability to make everyone around him better."
Messi has scored 32 goals and registered 16 assists in 41 games across all competitions this season.