City, the defending champion, is the only unbeaten team in the English top flight after 10 games but its capitulation in Europe has made Roberto Mancini the target of flak and frustration.
Mancini lost his cool twice this week, in a news conference before the 2-2 draw against Ajax and then immediately after the Champions League game in a finger-wagging confrontation with match officials on the pitch following some debatable decisions. That result left big-spending City highly likely to exit the competition at the group stage for the second straight year.
His actions are a surefire sign the Italian is feeling the pressure, at a time when ex-Barcelona coach Pep Guardiola is increasingly linked with City following the club's appointment of two former officials from the Spanish giant.
Tellingly, Mancini didn't attend his pre-match press conference on Friday, instead leaving the duty to assistant coach David Platt.
"He wears his heart on his sleeve," Platt said in defence of Mancini's actions. "It seems at the moment there are half-truths, stories that are big enough to last one day that are carrying on longer. That seems to be the case with us."
By the time the City-Tottenham match kicks off on Sunday, the champions are likely to be five points behind United, which rose to the top of the standings last weekend and on Saturday visits a struggling Aston Villa side it hasn't lost to away in the league in 17 years.
Portugal winger Nani was ruled out for 10 days on Friday with a hamstring injury but manager Alex Ferguson isn't short of attacking options with the prolific Robin van Persie, Javier Hernandez and Wayne Rooney helping United become the top scorers in the league so far on 26 goals.
"It's a healthy combination we have there," Ferguson, who has often played three up front this season, said on Friday. "Last year we lost the title on goal difference — I don't think that would happen this season."
Second-place Chelsea is the team separating the Manchester clubs at the top and the European champions are involved in the top match of the weekend, at home to Liverpool when John Terry is available after serving a four-match ban for racially abusing an opponent.
Instead of venting his anger at officials, Mancini may want to direct his ire at his defence. City has conceded some poor goals this season, especially at set pieces where markers have failed to track their men — both of Ajax's goals came via that route on Tuesday.
Mancini has also tinkered with formations, sometimes playing three at the back and in the 0-0 draw at West Ham last weekend playing three in attack. Enigmatic striker Mario Balotelli was substituted by Mancini in the second half after an ineffectual display, with the two Italians exchanging words on the sideline.
"He's the manager and sometimes he has to shout and argue with the players," City defender Pablo Zabaleta said after the Ajax draw.
"When any manager sees you drop points in a crucial game, they get very passionate and angry. Everybody wants to find the answers."
Mancini has Spain playmaker David Silva available after a hamstring injury, while defender Maicon and Joleon Lescott are also fit after knocks.
Sixth-place Tottenham surprisingly lost 1-0 at home to Wigan last weekend, leading to fans turning on manager Andre Villas-Boas at the final whistle, but returned to form on Thursday with a 3-1 win over Maribor in the Europa League. Jermain Defoe scored a clinical hat trick in that game, which saw Spurs change formation to a 4-4-2.
Like Mancini, Villas-Boas hasn't had the easiest rides this season — his first at the club — but the team has beaten United away in the league.
"It is hard for the fans. They've watched some good football over the last three or four years, maybe in a gung-ho style. But they've just got to be patient," Spurs midfielder Tom Huddlestone said.
"The manager's still getting his ideas across and the lads are still getting fully used to what he wants us to do."
Chelsea has picked up just one point from its last two league games, allowing United to take over as leader.
With Terry out suspended, the team has looked defensively suspect but the captain should return on Sunday even though he wasn't considered ready physically or mentally to feature in the 3-2 win over Shakhtar Donetsk in the Champions League.
"I don't think anybody's guaranteed a starting place," Chelsea manager Roberto di Matteo said, referring to Terry.
"He's certainly a fantastic player for us and he will continue to be so and continue to be our captain and our leader, when he plays."
Left back Ashley Cole is set to remain sidelined with an ankle injury.