But Reds supporters think the Belgian will play on the left with Sadio Mane getting the nod up front.
Roberto Firmino has been rested and is on the bench with Liverpool 2-0 up on aggregate.
The Reds can confirm a Champions League semi-final with Barcelona if they are victorious this evening.
And the inclusion of Origi has Liverpool fans predicting Mane will play through the middle.
One said: “So probably Mane plays upfront and Origi on the left #UCL #LIV.”
Another added: “Hopefully we see Origi on the left, Salah central and Mané back on the right sometime today. They won’t know what hit them.”
“Pace on the counter makes sense. Origi on left & Mane through centre. Milner & Gini great options to have come back into midfield. Full of energy & will be keen to put on a show to get their places back,” a third explained.
And a fourth said: “Expecting Origi to pull out wide a lot night, allowing Mane to make more central runs.”
Liverpool boss Jurgen Klopp has explained his reasons for starting Origi.
But he refuses to say he is resting Firmino.
“No issue, actually – just respecting the fantastic form Divock Origi is in for weeks or months already, and bringing in fresh legs,” the boss told BT Sport.
“That’s all, the same we do in midfield because we expect a very intense game, we expect a hard-fighting Porto side. So we need to be ready for that.
“Of course Bobby is ready for that but because he never gives himself a rest, from time to time we have to do it.
“But it’s not a rest actually, it’s bringing in Div and having that option: speed and all that stuff. That’s what we thought.”
Porto vs Liverpool takes place from 8pm this evening.