Reunions are supposed to be happy affairs. Not for Jose Mourinho.
Arguably his greatest humiliation came in October. As Manchester United lost 0-4 in the Premier League, "you're not special anymore" echoed around Stamford Bridge, sung by the fans who used to worship him.
When he visited Chelsea again in the FA Cup last month, he was taunted as "Judas". The Portuguese responded with a three-fingered gesture to indicate that, with three league titles, he remains their most successful manager ever.
Whether he can class his debut season at Old Trafford as success depends in part on whether he can take revenge on his past. He has lost rancorous reunions with Chelsea by an aggregate score of 5-0.
Should he fail to take revenge on his old employers, he will probably have to depend on the Europa League to secure a return to the Champions League.
Mourinho used to be the ultimate big-game manager. As, after Chelsea, United must face Manchester City, Arsenal and Tottenham, he could do with restoring that reputation because, if they are to finish in the top four, they will have to do it the hard way.
Chelsea were the last team to defeat United in the league, but the Londoners' programme mocked Mourinho in March for going from sixth to sixth on his long unbeaten run.
It is not quite true, but these are the teams with the most and least draws in the division. It explains why United linger outside the top four and Chelsea lead the way.
But as the Blues keep playing after Tottenham, their closest challengers could reduce the gap to four points again. Thus far Antonio Conte's men have responded to pressure, but only City have beaten Mourinho's United at Old Trafford.
Yet it is the Portuguese who needs to formulate a plan for victory.
Mourinho accused Conte of being defensive earlier in the season but, scarred by the 4-0 evisceration, he went to Stamford Bridge with what was in effect a back six, with Phil Jones man-marking Eden Hazard and, when Ander Herrera was sent off, he replaced the flair player Henrikh Mkhitaryan with the less creative Marouane Fellaini.
With Jones among the injured, he has fewer defensive options and more elsewhere.
He must decide whether to use Michael Carrick, influential against Anderlecht, as a third central midfielder. He could try testing Victor Moses' defensive credentials with the pace of Marcus Rashford, who was also brilliant in Thursday's 1-1 draw in Belgium. But he cannot pick a side as open as that was thrashed in the league or one as negative as that who seemed to be playing for a draw in the FA Cup.
Whereas Conte's team selection should be simple, Mourinho's is more complicated. He has a difficult balancing act. It is the sort he used to excel at. Now he needs to again.
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