Arsene Wenger v Jose Mourinho: In their own words
Arsene Wenger and Jose Mourinho meet on Sunday as Manchester United visit Arsenal with both sides chasing a top-four Premier League finish.
The pair are long-term adversaries and have clashed on a number of occasions in the past.
Here, Press Association Sport takes a look at the most memorable verbal sparring between the duo.
WENGER on Chelsea tactics: " I know we live in a world where we have only winners and losers, but once a sport encourages teams who refuse to take the initiative, the sport is in danger."
MOURINHO: " Wenger has a real problem with us and I think he is what you call in England a voyeur. He is someone who likes to watch other people. There are some guys who, when they are at home, have a big telescope to see what happens in other families. Wenger must be one of them - it is a sickness. He speaks, speaks, speaks about Chelsea."
WENGER: " He is out of order, disconnected with reality and disrespectful. When you give success to stupid people, it makes them more stupid sometimes and not more intelligent."
MOURINHO: "At Stamford Bridge, we have a file of quotes from Mr Wenger about Chelsea football club in the last 12 months - it is not a file of five pages. It is a file of 120 pages."
In February, Wenger said some of Arsenal's rivals had a "fear to fail".
MOURINHO: " Am I afraid of failure? He (Wenger) is a specialist in failure. I'm not.
"So if one supposes he's right and I'm afraid of failure, it's because I don't fail many times. So maybe he's right. I'm not used to failing. But the reality is he's a specialist because, eight years without a piece of silverware, that's failure."
In September, Chelsea beat Arsenal 2-0 at Stamford Bridge with both Gabriel and Santi Cazorla sent off for the visitors.
Wenger was critical of referee Mike Dean's performance but evaded a Football Association charge, something that angered MOURINHO: "In this country, only one manager is not under pressure. Every other manager is.
"We cannot be below par. We have to meet the objectives. There is one outside that list, but good for him. You know who.
"The one who can speak about the referees before the game, after the game, can push people in the technical area, can moan, can cry in the morning, in the afternoon, nothing happens. He can not achieve, keep his job, still be the king."
The Portuguese returned to the subject of Wenger when he was appointed United boss in July of this year.
MOURINHO: "There are some managers, the last time they won a title was 10 years ago, the last time I won was a year ago.
"I will never be able to work without success. That's my nature. If I have something to prove, imagine the others! To finish fourth is not the aim."
WENGER said on Thursday he hopes to call a truce in the 12-year spat.
"I am open always in life for everything, you know, for peace. But what is important when you are a competitor is that you give absolutely everything to win the next game.''