The former Argentina international doubts the Blues will overcome the Spanish giants to progress in the Champions League.
Chelsea recorded three straight victories before their 2-2 draw with Everton before the international break.
They beat German Bundesliga side Borussia Dortmund in a tense Champions League last-16 clash to progress to the quarter final.
Aguero told Stake: “I can’t just ignore the past and present of Real Madrid, they are the likely winners of this tie.
“Granted, Madrid is tried and true in these kinds of matches. Their history and recent showings prove as much. They’ll be the toughest of oppositions.
“But I wouldn’t expect that to make it an easy match for Real Madrid. Still, Madrid’s got the edge here.”