Aguero has made a big impact at the Etihad Stadium since his £38million club-record move from Atletico Madrid, scoring 13 goals in 19 appearances.
But Kompany said: "If you look at what has happened naturally for all the strikers here, we have only seen the best of Mario (Balotelli) this year, and only seen the best of Edin (Dzeko) this year.
"It's the same with David Silva, so it might be next year that we see the real Sergio. Maybe he has got another level on him.
"That's a great prospect for us, that players like Samir (Nasri), Sergio and Gael (Clichy), who are in their first year at this club and even though they have been performing exceptionally well, all still have another level to go to.
"That's the great thing about this team."