Coloccini describes his fellow Argentine as a "killer".
He told The Sun: "I know Sergio Aguero well, both from when we played against each other in Spain and also when we join up with the Argentina national team.
"He is a top player and we know if we give him any chances in the box, he will kill us. Sergio is a killer.
"When you play against him, you have to concentrate the whole time. He's a fantastic talent, the kind of player who may slip out of sight for 10 minutes and then, all of a sudden, he changes the game."