Walter Mazzarri is adamant he has a good relationship with Jose Mourinho and feels Zlatan Ibrahimovic is Manchester United's key man
The two men had a complicated relationship during their time together in Serie A, with Mourinho, who served as Inter coach from 2008 to 2010, verbally assaulting the ex-Sampdoria and Napoli boss on more than one occasion.
Nevertheless, Mazzarri is adamant he gets on with the Portuguese and is ready to have a post-match drink with his rival.
"I have a very good relationship with Mourinho," Mazzarri stated at a news conference.
"Sometimes the press look at what happened in Italy; the same with [Chelsea boss Antonio] Conte and Mourinho.
"It is normal when you fight for top positions that it happens but I have a very good, strong relationship with him. There is professional respect.
"Of course [I will invite him for a drink after the game]. No problem."
Watford will be looking to make it two wins in succession on Sunday after their 4-2 victory over West Ham last week, but Mazzarri realises a tough task awaits, singling out Zlatan Ibrahimovic as United's main dangerman.
"Ibrahimovic is the type of player I call eternal and immortal," he said.
"I have [coached] against him many times, he can make the difference on the pitch. We will try as we always do with great players but I also want to add that it's very important to keep in my mind Manchester United are not just about Ibrahimovic.
"[Wayne] Rooney, [Marouane] Fellaini; the whole squad, all of the players. They have a great squad and we have to be careful."