Sir Bobby – famed for his disastrous one-season managerial reign at Preston North End and for sporting the ropiest comb-over since the Hamlet cigar adverts – gamely hauls his creaking frame off the subs’ bench to croak lyrical about the immunity-boosting benefits of the bacteria-based beverage.
So potent is the elixir that Sir Bobby is able to attend a football match, befriend a youngster in red and white hat-and-scarf set (minus any official United club livery, of course) and even head a stray ball back from the crowd with that famous chrome-topped cranium.
While it hardly compares with Pele’s infamous stint as the, erm, face of Viagra, it’s still rather haunting to see a genuine English hero trudge along so stiffly, giving the enterprise a faintly tragic air.
It almost makes you yearn for the days of brother Jack’s sterling work for Shredded Wheat. Almost.