He has won La Liga eight times with Barca, the Champions League four times and Ballon d'Or world player of the year title five times.
Messi is reportedly close to signing a new long-term contract at Camp Nou and Guardiola said the way the Argentina worldwide handles an extreme level of expectation places him among history's sporting elite.
"He is one of the most privileged, gifted athletes of all time", Guardiola told Catalunya Radio.
The La Masia graduate scored 37 goals in 34 games in La Liga this campaign, while he created 78 chances and was successful with 61% of the take-ons that he completed.
Messi is now on £365,000-a-week, but the club have offered him an increase of 37%, as they seek to tie the 29-year-old down. "They chased Real Madrid to the final day of the [LaLiga] season".
They lost 0-3 on aggregate in the Champions League quarter-finals to eventual beaten finalists Juventus.
Barcelona's decision of roping former Athletic Bilbao manager Ernesto Valverde as their head coach has also been backed up by the City manager.
Guardiola enjoyed much success when in charge of Barcelona, with Messi a major part of his team.
Messi was runner-up to Real Madrid's Cristiano Ronaldo in the Ballon d'Or earlier this year.
"It's what I always dreamed and what I always wanted". He is a sensible person and he knows a lot about football.