‘Inevitable’ was the word Martin Keown used to describe the fate of Manchester United boss Erik ten Hag following Thursday’s alarming collapse away to Chelsea, the Red Devils somehow managing to turn a 2-0 deficit into a 3-2 lead and still lose the game ten minutes into second-half stoppage-time. Was this the straw that breaks the camel’s back, Manchester United’s soft centre exposed brutally by the red-blooded Cole Palmer in front of new co-owner Sir Jim Ratcliffe? Keown, a three-time Premier League champion with Arsenal under Arsene Wenger, knows what it takes to succeed at the top end of th…