Arsenal's previous trip to Anfield ended in a 5-1 defeat in the corresponding fixture from 2013-14 in February - a match that saw Brendan Rodgers' side leading 4-0 after 20 minutes.
Wenger admits that the drubbing still hurts, but he believes Liverpool do not pose the same attacking threat as they did last season.
"Every defeat leaves a scar in your heart," said the Arsenal boss.
"Last year Liverpool scored over 100 goals. Now they're not on the same trend. They came off the blocks very strong last time."
The trip to Merseyside also sees forward Alexis Sanchez come face-to-face with Liverpool, who he reportedly turned down in favour of a move to Arsenal in July.
The 26-year-old has quickly become a fans' favourite at the Emirates Stadium with nine goals in 15 Premier League appearances.
And Wenger is delighted that the Chile international chose to join his side from Barcelona in the close-season.
"Every great player has the choice to play where he wants and he chose us," he added. "We're very happy.
"I told him the way we play football will suit him and all players want to play in the Champions League."
Wenger confirmed that late fitness checks will be given to Theo Walcott, Alex Oxlade-Chamberlain and Nacho Monreal, but Laurent Koscielny definitely misses out.
