Manchester United managerial great Sir Alex Ferguson admits he's happy he retired before Jurgen Klopp took charge of Liverpool.

The two sides meet again on Sunday in a clash which could provide a strong indication of United's title credentials this season, amid doubts over their ability to last the course.

"United against Liverpool is the game of the season - the most successful sides in the country," he said during a 'talk with legends' where Klopp was present.

"I had to build a club not just a team to surpass them.

"Thank goodness I've retired, because when I see Liverpool's performances over the last two seasons - phenomenal."