"The people around the club, when we start to win a lot of games, they start to say a lot of things and it's not good", he continued.
And with United also thought to be contemplating a return to the U.S., that could raise the possibility of another Manchester derby taking place overseas.
And against a side like City who would be looking to punish United for the slightest of gaffes in midfield, United can go into the clash assured of a better defensive covering in midfield with the likes of Herrera and Blind.
The men's September 2016 reunion promised much, Guardiola's slick City wiping the floor with United in the first half before a Claudio Bravo blunder enabled Zlatan Ibrahimovic to make a game of it in the second. Given Mourinho's habitual third-season problems, the likelihood of further upheaval at Chelsea in the summer and perhaps mounting dissatisfaction among Tottenham's young players as they see their peers earning far more elsewhere, City may find themselves without a serious challenger in the short-to-medium term. And he thinks United's history of playing attacking football is so important that he would have given old teammate Giggs the job when Ferguson retired in 2013.
Manchester City's unbeaten season finally came to an end with the 2-1 loss to Shakhtar Donetsk in the mid-week Champions League fixture.
Seven months on City look nearly transcendent, their sublime and devastatingly effective possession football reminiscent of Guardiola's great Barcelona team.
Having won their last 13 league games, they can set a new mark for successive wins within an English top-flight campaign if they prevail on Sunday.
That's because of his straight red card in last weekend's 3-1 win over Arsenal. Despite being on the sidelines himself, Pogba believes that United can win the derby.
"And secondly, that I wanted to show what I could bring to the team, to prove myself".
There was a glint of the old malice in Mourinho's eye after United's win over CSKA on Tuesday, when he suggested Guardiola was being untruthful by expressing doubts about the fitness of Spanish playmaker David Silva.
It is a look Guardiola knows all too well and its reappearance indicates the biggest managerial rivalry of recent times is about to erupt again.