Meanwhile, the Reds are sweating on the fitness of striker Mohamed Salah.
A hitherto spectacular second season under Guardiola for City has unravelled in the past week as they were thrashed at Anfield in the first leg, and then let a 2-0 lead slip with the chance to seal the Premier League title against Manchester United in a 3-2 derby defeat on Saturday.
Even if City go out, Guardiola could badly do with them winning at least the match to restore battered morale ahead of a tough league match with in-form Tottenham Hotspur at the weekend with the Premier League title theirs for the taking.
The trouble for Guardiola is even if Salah — who scored his 38th goal of the season in the first leg before limping off — is not able to play a role, Liverpool have enough firepower up front in the shape of Roberto Firmino and Sadio Mane to hurt City.
Liverpool manager Jurgen Klopp said on Monday Salah was more of a ‘yes’ than a ‘no’ for the trip to the Etihad, though whether he plays will only be decided later on Tuesday.
More encouraging for Liverpool fans is that Guardiola has lost six times in the knockout stages and four of the teams who bested him went on to lift the trophy.
The Spaniard believes that were his team to pull off an extraordinary comeback it would take Abu Dhabi-backed City — who have only reached the last four of the competition once — to another level.
“I know we are judged on results, but on the performances my team is extraordinary. It is not comparable for many others, it’s top,” Guardiola, whose side still boast a 13-point lead at the top of the Premier League, said.
“They are exceptional, so I will be close to them no matter what happens between now and the end of the season. It’s a joy to be manager of this team, even three days ago the way we played.”
– ‘I’m never nervous’ –
One area of hope for Guardiola is that Liverpool’s Achilles heel has been its defence although Dutchman Virgil van Dijk has added some steel since joining from Southampton.
The Dutch captain will be examined to the full at the Etihad, though, where Liverpool were thrashed 5-0 earlier in the season, albeit before Van Dijk joined from Southampton.
Klopp’s men were also crushed 4-1 by Tottenham and involved in thrilling 3-3 draws at Arsenal and Sevilla as they were routinely torn apart on their toughest travels, before the addition of the tall Dutchman.
Van Dijk, though, says he is not nervous at all about the impending clash — indeed, if anything, the 26-year-old admits to being too relaxed.
“I always have been, sometimes a little too much,” van Dijk told journalists.
“Sometimes that cost me back in the day. What we do as players is something you need to enjoy.
“I’m never nervous.
“I’m just excited. I think, ‘Look where I am. Playing for the semi-finals of the Champions League with my team. Just enjoy it and love it.'”
Van Dijk will do well to remain so relaxed given he faces a City attack bolstered by the likes of Sergio Aguero, who missed the traumatic United defeat, and Kevin De Bruyne, who only came on as a second-half substitute.
If Guardiola is to seek inspiration in terms of a miraculous comeback, then United set him an example last Saturday of how quickly a match can turn on its head.