And now, even more oddly, their season appears to have been turned into some weird freak sideshow of Blues boss Antonio Conte getting embroiled in a bitter war-of-words with Manchester counterpart Jose Mourinho.
The next day Conte reminded Mourinho that he was once an animated young manager - the former Real Madrid boss famously ran along the touchline at Old Trafford in 2004 to celebrate his Porto team's victor against United in the Champions League. A gust became a storm.
Writing in his column in the Herald, former Manchester United player Giles said the Italian's description of Mourinho was apt.
Conte has looked to bring an end to the row but said he "will not forget" about the feud.
"You see how Hazard goes down and you see how quickly he takes the penalty when he gets the penalty", he told reporters. "Then I asked for a retrial by court and then they declared it nonsense". Antonio Rudiger is the man most likely to make way. "I know him very well".
"He has the flawless platform to make a judgement given the fact that Conte won the title with the same players Mourinho accused of betraying him before he was sacked by Chelsea".
Mourinho has twice managed Chelsea. "If Conte used the 'senile" word he certainly made a mistake.
Chelsea were held to a goalless draw by Arsenal at Stamford Bridge in the Carabao Cup Semi-final and will get a replay at the Emirates. This isn't a problem between the clubs.
Former Chelsea gaffer Carlo Ancelotti, who has also been linked with Arsenal, could be set for a return to the Bridge, while the out-of-work Thomas Tuchel and Atletico Madrid boss Diego Simeone are two other names in the frame. "He didn't play and I think this season if you consider his injury for a month, he had his chance", the Italian manager added.
Chelsea and United are scheduled to meet at Old Trafford in the Premier League on February 25.