The former Bayer Leverkusen attacker had offers from both giants, but ultimately decided to leave home and the Bundesliga for Merseyside.
Wirtz's parents were the key representatives for the player at the height of negotiations.
"Arne Slot presented his playing philosophy, the team tactics in possession and pressing, and how Florian can develop his strengths in these areas," his father, Hans, told Der Spiegel. "This made a decisive impression on Florian. The training conditions in Liverpool were also totally impressive.
"Arne Slot has impressed Florian on the pitch. He's also a very pleasant person. "Florian's best coaches have always been those who gave him plenty of freedom.
"And those with the greatest empathy have also reached Florian. He finds the game in England interesting because it thrives on pace and dynamism."
Amazing Hoeness gesture
On Bayern, Hans also explained: "The situation with Bayern was difficult because Uli Hoeness and Karl-Heinz Rummenigge made incredible efforts and also clearly analysed the sporting possibilities.
"I have the greatest respect for Uli Hoeness and his lifetime achievements. After Florian's cruciate ligament tear in 2022, he selflessly helped us quickly get an appointment for the surgery in Innsbruck.
"We are still grateful to him for that. That's why the final phone call with Uli Hoeness was very difficult for me. We had spoken several times beforehand, so he was as objective and fair as I'd ever known him.
"But of course, he couldn't hide his disappointment. After all, he had personally worked hard to secure this transfer."