Fabinho has been out of action since sustaining an ankle ligament injury during November's 1-1 draw with Napoli in the Champions League group stages.
Matip, meanwhile, has been nursing a knee problem he aggravated when the Reds last met United - another 1-1 draw at Old Trafford.
But both men are back in full training and will be available to take on Ole Gunnar Solskjaer's team at Anfield this Sunday.
Klopp said: "Joel [Matip] and Fabinho, they trained completely normal yesterday and the day before.
"That means they are likely to be in the squad."
The German also revealed that Dejan Lovren (hamstring) will resume training alongside his teammates next week, potentially putting him in contention face Wolves.
But he refused to put a timeframe on recent injuries to James Milner (hamstring) and Naby Keita (groin).
He added: "The other three are not [ready] but they are getting closer and closer.
"Dejan [Lovren] I think will train 100% from Monday on, the other two [Milner and Keita] I don't know exactly."