Aguero, who is the highest-scoring non-Englishman in Premier League history with 181 goals, will leave the Etihad at the end of the season after City confirmed on Monday that he would not be offered a new contract to replace his existing deal, which expires on June 30.
Speaking exclusively with ESPN Brazil, Guardiola compared Aguero to Messi and Maradona as other Argentina greats who have etched their marks in Europe's top domestic leagues.
"Maradona conquered Italy, Messi did it in Spain, and Aguero has done it in England, his numbers speak for themselves," Guardiola said. "When you have that internal fire, play with that anger, his incredible talent comes out, he can win games on his own."
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Aguero netted 257 total goals in 384 appearances and won four Premier League titles, one FA Cup and five League Cups. Among the highlights of Aguero's City career is his injury-time winner against Queens Park Rangers on the final day of the 2011-12 season that secured the club's first English title in 44 years.
Injuries, and a spell on the sidelines with COVID-19, have restricted Aguero to just four Premier League starts and one goal this season. In total, he has made just 14 appearances in all competitions, scoring three goals.
Aguero is now fit, however, and ready to contribute to City's push for an unprecedent quadruple of Premier League, FA Cup, Carabao Cup and Champions League this season.
"He is an extraordinary person, and we still have another month and a half to win things and score goals," Guardiola added.