City forward
Aguero has been suspended for three games following an attempted elbow on West Ham defender, Winston Ried.
The suspension means that the Manchester City first choice striker will be missing in the derby on Saturday.
Iheanacho, however, is ready to stand-in for the Argentine.
"Sergio's suspension is a big loss but we have a lot of big players to turn to," the forward told The Sun.
"If I get picked I'm going to do my job.
“Games like this mean a lot and it doesn't come bigger than a derby."
Iheanacho has been involved in all City games this season before an injury in the preliminary Champions League game Steaua Bucuresti.
The injury made him missed out in their last league game, a 3-1 win over West Ham.
He, however, returned in Super Eagles 2017 Africa Cup of Nations 1-0 win over Tanzania, scoring the only goal.