As the record goalscorer in Premier League history, Shearer's views carry a lot of weight.
The BBC pundit, who scored 313 goals in 622 career games for club and country, used his latest column on Coral to disagree with Pellegrini's suggestion that his players were playing too many games following their 2-0 defeat to Stoke City at the weekend - as reported by the likes of ESPNfc.
Stoke’s superb victory earned them plenty of plaudits and was yet another surprise result in this most wide open of Premier League seasons.
In truth Mark Hughes' side could easily have won by more against City who Shearer said 'deserved a good hiding'.
City have since bounced back with a 4-2 win over Borussia Monchengladbach to seal top spot in their Champions League group on Tuesday night.
'I don't buy it'
But former Newcastle United striker Shearer said the Citizens were 'all over the place defensively' in the Premier League.
"They looked tired and leggy and the performance overall was very poor," Shearer wrote on Coral.
"I don’t buy into what Pellegrini has said when he suggests his players are playing too many games.
"They have limitless resources and a bigger and better squad than anyone and so he cant use that as an excuse.
"City spent a lot of money on their defence and they have yet to get it right. As a centre forward, you’d fancy your chances coming up against that defence that played on Saturday."
In City's defence they were without a number of key players against Stoke with Sergio Aguero, Yaya Toure, Vincent Kompany and Pablo Zabaleta all missing.
Take such influential players out of any Premier League side and they will struggle.
City's riches have left them open to attacks like this from pundits so Pellegrini must be more mindful of the tactics he uses to protect his players for criticism in future.