Here, we look at some of the talking points ahead of the contest
Moaning Mourinho
Manchester United boss Jose Mourinho turned his ire on Antonio Conte, his successor at Stamford Bridge, after Chelsea beat United 4-0 in the Premier League in October
Mourinho took exception to Conte geeing up the crowd when the Blues were already four goals clear
It took some of the attention away from his side's poor performance and expect more moaning from Mourinho if United are beaten again - or wild celebrations if his side can advance to the semi-final at the expense of his former club.
Travel Tribulations
Mourinho has continually bemoaned United's hectic fixture list, pointing to Chelsea's light schedule in comparison, but without acknowledging his role in the Blues' absence from European football
Being drawn to play Rostov in the Europa League hardly helped matters and now he must manage his options for next Thursday's second leg and the Chelsea tie
Conte can field a first-choice XI
At least Mourinho cannot complain about a replay - the quarter-final must end on the night and could go to penalties.
'Rats' attack
Diego Costa, Eden Hazard and Cesc Fabregas were branded 'rats' by some of their own supporters in December 2015 in the days after Mourinho's sacking for a second time
The trio were perceived to have under-performed for the self-proclaimed Special One
But they have recovered their status in the eyes of Blues' fans, helping power Chelsea towards the Premier League title
And now their former boss stands in the way of a possible league and cup double.
Bus to be parked?
With Zlatan Ibrahimovic suspended and Wayne Rooney, Marcus Rashford and Anthony Martial seemingly not fully in favour, where will Manchester United's goals come from? Chelsea have been lethal on the counter-attack this season and have lost just once at home and are seeking a club record 13th successive home win
They may have to take more of the initiative in what could be a cagey encounter
Expect the United bus to have its handbrake on and a wheel clamp in place which Chelsea will have to try to remove.
Manager receptions
Mourinho, for so long adored by Chelsea supporters who were reluctant to see him leave in September 2007, has lost that affection since his move to Old Trafford
His October return to Stamford Bridge went by in almost apathy as Chelsea fans focused their attentions on Matthew Harding on the 20th anniversary of the former Chelsea chief's death
And now Conte is the favoured one, with Mourinho considered just another opposing boss.
Source : PA
Source: PA