Aguero has been in fine form as of late, and has found the back of the net in all four of his Premier League games against Liverpool at the Etihad Stadium.
However, Klavan - who in combination with Dejan Lovren kept Aguero at bay in the reverse fixture at Anfield in December - is looking forward to going head-to-head with the former Atletico Madrid forward once more.
"I think fearful is not the right word," Klavan told the Liverpool Echo.
"He is a world class striker but a lot of teams in the Premier League have world class strikers so it's nice to play against them.
"There is always a lot of respect for the strikers I play against but fear is not the word.
"The game [in December] was a great game from our side. For me, the first time to play against Aguero. He is a great striker.
"But from our side it was a really good team effort. We didn't have so many chances in the game.
"We scored one and we defended really well, also in the second half when there was more pressure in the game, we were defending together and that was the key."
While Klavan has only faced Aguero and City once before, the Estonia defender has experience facing Pep Guardiola's sides, having featured for Augsburg against Bayern Munich during his time at the Bundesliga club.
"They always want to play really nice, attractive football," he said of Guardiola sides.
"It was always very clear to see when he was manager of Bayern Munich, but maybe in England it is a little bit different.
"In the Bundesliga, Bayern is the best team but in England the league is so equal, I think also in the beginning of the season you have at least six teams who can become champions so it is not so easy here."