Speaking after Tuesday's 2-1 win over CSKA Moscow, Mourinho was not buying it and grouped Guardiola's claims with those of Arsene Wenger, the Arsenal manager who said Alexandre Lacazette would not face United last weekend before he promptly played and scored in the Emirates Stadium thriller that the visitors won 3-1. He will now get that opportunity in the fiery atmosphere of a Manchester derby.
The incident came after Raheem Sterling's late victor sent the Etihad into pandemonium, setting them up for a record-equalling 13th consecutive Premier League victory against West Ham on Sunday.
Shakhtar started aggressively and took the lead in the 26th minute when Bernard cut in from the left side of the box and curled a shot inside the far post, beyond the reach of goalkeeper Ederson.
'I have had similar deciders in my career but this is the first time I have had such a game in the Champions League'. Guardiola ditched it in September and City have played their best football since then. Phil Foden showed good composure although this was a tough test for the 17-year-old in an unfamiliar wing back role.
While Benjamin Mendy waltzed into the first-team picture on account of little competition - prior to injury - Bernardo has found his route to the pitch blocked by the likes of Sane, Kevin de Bruyne, Raheem Sterling and namesake David Silva.
The French midfielder added: "People don't see this, don't speak about this, but every time we have important players that get injured when there is important games". Yaya Toure and Tosin Adarabioyo, who have only seen action in the Carabao Cup, also started.
"I assure you, sooner or later we will lose, but the next day we will recover". But it's not always about winning or losing - it's about playing the same way we always do and giving our all.
City will train again back in Manchester on Friday afternoon and by kick-off on Sunday the vast majority of their strongest XI will have benefited from a midweek rest. That is nine of 10 outfielders who have hardly been overworked of late.
Pep Guardiola's side lead their city rivals by eight points ahead of the derby match at Old Trafford and if they win their 14th straight league match, they will move 11 points clear after just 16 matches of the season.