The pair have both moved from Bayer Leverkusen in recent weeks.
"I'm looking forward to playing for Liverpool and of course my good friend Florian Wirtz joining as well. That makes it all extra fun," Frimpong told ESPN.
"I also already know some players from the national team, so yes, I'm really pumped. I can't wait to get started."
Frimpong has joined Holland teammates Virgil van Dijk, Ryan Gravenberch and Cody Gakpo at Liverpool. Frimpong also appreciates now joining countryman Arne Slot at Anfield.
"When I first spoke to him, I immediately noticed that he was interested. He said that he really wanted me at Liverpool and that I would fit in well with the team," he said.
"When you hear that Arne Slot wants you, and you get to play for Liverpool at the same time, it's a pure honor. How could I say no?"