Liverpool unveiled their new Main Stand before their 4-1 hammering of Leicester last month.
But the cheeky United fan has waited until the day of the first North-West derby between Jose Mourinho and Jurgen Klopp to reveal his gag.
He was part of the team that carried out the 100m expansion work to add a third tier to Anfield’s Main Stand and boost crowd capacity at the stadium by 8,500 to a total number of 54,074.
And the builder sneakily accessed the underside of the stand’s roof and snuck inside bobble-head toys of Ferdinand and Giggs, and a vintage United shirt.
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