The Anfield club and Premier League champions reportedly paid €117 million to secure the Bayer Leverkusen playmaker.
However, the former Liverpool manager wonders what position Wirtz will occupy in Slot's team for next season.
What Klopp said
Wirtz didn't feature in the 3-1 preseason victory against Preston, despite manager Arne Slot giving minutes to fellow new arrivals Giorgi Mamardashvili, Jeremie Frimpong, Milos Kerkez, and Freddie Woodman.
According to the Daily Mail, the German international's absence was due to a personalised fitness plan.
"Yes, he will make his mark, although I don't know exactly what position Arne has in mind for Florian," Klopp said, also quoted by the English newspaper.
Wirtz primarily played as an attacking midfielder or second striker for Bayer Leverkusen last season, scoring 16 goals and providing 15 assists.
Alternatively, Slot could deploy Wirtz as a false nine or even on the left wing, should Luis DÃaz's departure be confirmed.
Following Wirtz's move to Liverpool, Klopp told RTL/NTV, via Abola, "It's going to be absolutely fantastic, I'm sure. It's very difficult to strengthen a title-winning team, but Liverpool have done it. They've signed an exceptional talent. I can't wait to see him play."