Sir Alex and the United squad joined Hublot boss Jean-Claude Biver at Old Trafford on Friday afternoon to unveil the largest clock ever built by the Swiss company.
Standing at a height of 10m, it was specially created for the reigning English champions and features four clock faces. Sir Alex described the monument as "an amazing clock".
"It's incredible," he told MUTV. "And it's also going to act as an information centre for fans so they can find out what's going on in Manchester.
"I think this is very unique – there's nothing else quite like it."
The structure is comprised of a 10m tower in the shape of an H (the Hublot logo) and holds four two-metre-diameter clock faces. Located in the car park in front of East Stand, the clock tower overlooks popular gathering points for fans on matchdays.