The Argentina midfielder suffered a cut knee in victory at Sheffield United.
"Macca doesn't look good, so we have to see day by day," said Klopp ahead of Saturday's trip to Crystal Palace.
"They were pretty hopeful after the game that it was not serious. It's not that serious, but in the period of the year if you are out for five days, it's 12 games pretty much."
Klopp added: "I don't expect him to be ready for [Saturday]. I don't know about Thursday or Sunday after that, so it's pretty much stop and go. We have to see."