Sir Alex turned 80 on New Year's Eve and many in the world of football have paid tribute to one of the greatest managers in the history of the game and Klopp was keen to hail the German for his achievements.
"I know it's Sir Alex Ferguson's birthday today, so happy birthday Sir Alex, it's a big one. And my assistant Pete Krawietz turns 50 today, so another big football brain has an important birthday," he told Sky Sports.
A number of current Red Devils players paid their tribute to the legendary Scot, with David de Gea and ex-striker Robin van Persie - who both played under Ferguson - wishing him happy birthday on social media.
"Happy 80th to the greatest - Sir Alex Ferguson," wrote De Gea, while Van Persie added: "Happy 80th birthday Sir Alex! Wishing you all a happy and healthy 2022, stay safe and positive."
United talisman, Bruno Fernandes too sent a message to Sir Alex on social networking site, Twitter, tweeting, "Happy birthday Sir Alex! A living legend of Man Utd, an icon of the world of football."
The legendary Scot is considered to be the greatest manager in the history of club football, spending 25 years at Manchester United, leading them to 13 league titles, five FA Cups and two Champions League honours.