We’re celebrating Alex Ferguson’s birthday by looking at his two greatest teams of each century

73 and people are still whinging for his return.

Alex Ferguson could walk back into the United dressing room tomorrow and squeeze another title out of them he's that good. But, as the end of a 2014 that has seen his successor David Moyes axed, van Gaal begin to rebuild the empire and Roy Keane release his second book, the retired managerial legend celebrates his 73rd birthday in the peace and, although he may not be best pals with Keano anymore, we still respect Fergie. We already looked at 28 things that have changed since the Scot left the Old Trafford hot seat but, to mark another landmark in one of the finest footballing careers of all time, we're looking back fondly on some of the amazing talents that Ferguson brought or nourished in Manchester. Across four different decades, Alex produced 13 league titles, continually rebuilding teams right up until his retirement in 2013.  So we've cobbled together his greatest team of the 20th century against his best XI of the 21st century. A number of those players could've entered either side at their ease but, naturally, we only had room for one - not that Fergie will be thanking us for it. Two cracking sides.  The only question remains: who would win?