Fonseca masterminded an unlikely 2-1 victory over Premier League giants Manchester City on Wednesday - securing Shakthar's path into the next round.
Pogba fanned the derby flames in a Saturday interview in which he quipped he hoped City piles up injuries - only to then rule himself out of this Sunday's game by being sent off for stamping on Hector Bellerin in United's 3-1 win at Arsenal.
With City now sitting atop the league table, clear of Sunday's opponents United by eight points, it already looks like they might have the title sewn up before Christmas.
"It's a must-win game".
"I would prefer to win (games) earlier but the Premier League is the Premier League", Guardiola said.
The fixture will see Premier League leaders City visit their closest rivals in a crucial match, but they reportedly have seen a request to film footage for their Amazon Prime documentary turned down.
"West Ham didn't want to play".
Yet despite this commanding run of results and an eight point buffer on closest contenders Manchester United, Guardiola knows that City still can not avoid a slip up over the holiday period.
Wenger fires back at Mourinho over playing Lacazette against Manchester United
He said: 'I know what I'm capable of doing, I just want to stay fit and healthy and let my football take care of itself. The only player, apart from long-term absentee Santi Cazorla , who has is struggling with an injury is Shkodran Mustafi.
W/Cup Last Opportunity For Current Argentina Team - Messi
We spoke about it through messages, it was a good thing that he had this period of absence. They reached the final at the 2014 World Cup in Brazil but suffered defeat to Germany.
Chelsea do not fear Barca or PSG-Hazard
Pot 1: Manchester United , Paris Saint-Germain, AS Roma , Barcelona, Liverpool , Manchester City , Besiktas , Tottenham Hotspur. Pep Guardiola's men have shown little sign of fatigue on Champions League nights, storming to the top of Group F in style.
"Today I learned a bit, like a manager, to tackle it differently", he said. "We can play the same way".
"It has been a tough week for Manchester City, but a good one, though it has also been a good week for Manchester United as well, in terms of competitors chasing City", Neville told Sky Sports News.
"I heard about the Fergie time", Guardiola said.
The Citizens are soaring at the moment and are now on a win streak of 19 games in all competitions - their last defeat in the calendar year coming all the way back in April.
"That is why I'm happy because we were able to do it in the second half. He's not given him any help or any cover and Shakhtar have run freely at City without any real pressure on them", he added.
Guardiola said, "We started really well but their first goal was magnificent while their second I felt we didn't defend too well".
"But I don't think we will be in trouble".
"We know Man United have a very good team as well but we will play our game and try to control the match, to be better than them and bring the three points back home".