Jose Mourinho has apologised to Manchester United fans following the humiliating 4-0 defeat at the hands of his former club Chelsea at Stamford Bridge last weekend.
First-half goals from Pedro and Gary Cahill saw Chelsea go 2-0 up after 21 minutes before Eden Hazard and N'Golo Kante compounded United's miserable afternoon after the break.
The result saw United fall six points behind leaders Manchester City in the race for the Premier League title and Mourinho has acknowledged their display was unacceptable.
"We can only apologise to our sensational fans after a poor show at Chelsea," Mourinho told the United matchday programme for Wednesday's EFL Cup encounter with City.
"As the leader of this squad I want to start by saying sorry to all the Manchester United fans around the world. Sunday's 4-0 defeat at Chelsea was not a United result; it was a result that has made us all extremely sorry for all our supporters and we all apologise for it.
"Once again at Stamford Bridge our fans were sensational. I cannot think of another set of supporters who would be singing for 90 minutes like that when their team was losing. They were a credit to the club and I feel so sorry for them that the result could not match their performance.
"Even in the best periods of the club's history there have been heavy defeats - I have beaten United 3-0 as a manager and 3-1 twice - but we all know that we cannot accept results like the one on Sunday.
"There is only one way I know to react to this kind of result and that is with hard work."