The pair returned to full training this week after a recent bout of illness but aren't considered fit enough to feature against the Portuguese league leaders.
Klopp has no other major fitness concerns but insisted he will take no risks with players who felt the effects of an 'intense' win over Newcastle United on Saturday.
He said: “We had a few knocks after the game, an ankle here and a muscle there; not a muscle injury but dead legs and stuff like that. It was an intense game, so we need to wait a little bit.
“But, [there are] no major things so far that I heard about.”
Porto boss Sergio Conceicao is facing a less difficult team selection for Tuesday's game, with a spate of fitness issues likely to make many of the decisions for him.
The Portuguese league leaders have travelled to Merseyside without the injured quartet of Danilo, Alex Telles, Francisco Soares and Moussa Marega.
On the tough task of coping without the latter, Conceicao said: “Moussa Marega offers an awful lot when he plays in a two-man attack. His replacement is likely to offer different qualities, so our playing style might change as a result.
“It will also depend on the flow of the game. We’ll have to wait and see how things pan out.”
However, striker Vincent Aboubakar has recently returned to fitness after sustaining a hamstring problem, and will be in contention to feature at Anfield.