Some players might have sulked or run from the challenge but Agüero responded to the arrival of Brazil striker Gabriel Jesus by evolving his game as City evolved under Guardiola.
What has emerged is a much more complete striker, one who helps to facilitate moves that so often culminate in the ball being walked into the net rather than solely being a player who applies the final finish.
City have scored 60 goals from inside the six-yard box in 2½ seasons under Guardiola – eight more than they mustered in the previous four campaigns – and Agüero is an obvious beneficiary of that, his average distance from goal when he scores dropping from 13.19 yards in Manuel Pellegrini’s final two seasons to 10.38 under Guardiola.
“Guardiola wanted more for the team and it is credit to him that he was prepared to push one of his top players to the point where he was thinking, ‘Should I stay or should I go?’ in the hope of getting what he wanted,” Carragher said.
“I remember Guardiola was pictured in a restaurant with Agüero and his agent looking quite animated in that first year. I think a lot of that might have been to do with him wanting more from him, and even when you heard Guardiola talking about Agüero and Jesus after games, he seemed a lot warmer towards Jesus.
“In some ways, I think Jesus has been used to get more out of Agüero and Agüero has seen the benefits of that.”
As Sarri and his Chelsea players may again discover to their cost this weekend.