The Premier League champions closed to within four points of Jurgen Klopp's leaders at the summit thanks to goals from Sergio Aguero and Leroy Sane either side of Roberto Firmino's second-half equaliser.
Fernandinho sat out City's back-to-back defeats against Crystal Palace and Leicester City last month, with John Stones and Ilkay Gundogan providing uneasy alternatives at the base of Guardiola's midfield as Liverpool were gifted the initiative.
And, in a season when star man Kevin De Bruyne has been limited to a solitary league start due to medial knee ligament injuries, Guardiola knows he can ill afford his 33-year-old midfield general spending any more time on the sidelines.
"Fernandinho's specific qualities, we do not have a replacement for him – his kind of duels, the way he is going backwards," said the City manager.
"He is an incredible, outstanding player for us. Against Liverpool he showed it again.
"And pray, pray [for him] to be fit for as long as possible."
Another veteran of City's previous title triumphs, Aguero, opened the scoring on Thursday by beating Alisson with a thunderous finish from an almost implausible angle.
Friday mood! pic.twitter.com/X4QUAHP2FO— Fernandinho (@fernandinho) January 4, 2019
Guardiola ranks City's all-time top scorer Aguero and Fernandinho among a select few of his first-team squad for whom winning is akin to a drug – proven characters who could be pivotal should the battle with Liverpool go to the wire.
"Always he responds," the ex-Barcelona boss said of Aguero. "He has these incredible numbers.
"I have a lot of respect for the players who stay 10, 11, 12 years – every year doing that. They are the ones I respect the most.
"Everybody can make an exceptional season or good moments in six months or two seasons.
"But players like Vincent [Kompany], like David [Silva], like Sergio, like Nicolas Otamendi, who every single year are there competing with the desire to do more and more and more...
"Winning is so addictive. It is something when you taste it, you go, 'wow, I want more of that'."
The hedonism of midweek at the Etihad Stadium, where Guardiola credited a raucous home crowd for being "close to us more than I ever saw before in my period here", gives way to a Sunday visit from Rotherham United in the third round of the FA Cup.
Then comes the first leg of an EFL Cup semi-final against Burton Albion as City continue to battle for trophies of four fronts.
As much as he welcomes that challenge, Guardiola conceded there might be more enjoyable ways to spend the English winter.
"I would like to have two months of holidays right now, definitely," he added. "This month was really tough but it is what it is.
"We want to become a top, top club. You cannot deny any game, you cannot drop any competition.
"I don't know how we are going to be. Maybe if we didn't play in the Carabao Cup it would be easy for our recovery. For example, Liverpool are out [of the EFL Cup] and have more time to prepare the Premier League.
"But I prefer to be in [City's] position. We have enough of a squad – Kevin is coming back, Gundogan is coming back. Everybody is going to rotate and everybody is going to play. It is the only way."