Lallana, 29, missed Liverpool's FA Cup defeat against West Brom due to what Klopp described as a "little muscle tear" in his leg.
The German said the problem could force the former Southampton player to sit out the crucial game against Tottenham at Anfield at the weekend.
Lallana has only made six league appearances for Liverpool this season after being sidelined for a three-month period with a hamstring injury.
"He's not ready for Huddersfield," Klopp was quoted as saying by the Liverpool Echo. "Medical department told me no chance for West Brom, no chance for Huddersfield and a chance for Tottenham.
"After Tottenham for sure, but before Tottenham I don't know exactly."
Jay Rodriguez scored twice as West Brom deservedly beat Liverpool 3-2 in an FA Cup tie that was dominated by video assistant referee (VAR) decisions.
Klopp's hopes of winning a first trophy at Liverpool now rest on the Champions League, with the Reds facing Portuguese side Porto in the round of 16 next month.
The German said he expected a reaction from his players after their FA Cup exit and dismissed suggestions that the club's thrilling win over Premier League leaders Manchester City earlier this month had made the squad complacent.
"We have to show in the next game what we really want," Klopp was quoted as saying by the Guardian.
"There are a lot of games to play, a lot of big challenges waiting for us and we have to be ready.
"After each defeat, if you learn from it, then it makes a little bit of sense. If you don't learn from it, then it makes absolutely no sense. Of course the pressure increases in a situation like this, the pressure we make on ourselves, but that's how it is."