"Joe, we still wait for final assessments, stuff like that, so we can really figure out what it is exactly. He's not available for Chelsea," Jurgen Klopp said during his pre-match press conference.
Meanwhile, Can has been out of action for the Reds since picking up a back injury against Watford on March 17. The German international has spent much of rehabilitation away from Liverpool and Klopp has ambigiously suggested Monday is an "important day" for the midfielder.
"We are in contact with Emre. An important day is next Monday and then we can make the decision if he starts training with us or not immediately," Klopp added.
“It would only be good news for the final, probably not for the last game of the season."
Lallana, who has had a stop-start campaign due to injury, is back in full-training but could still miss out against Chelsea due to a lack of match fitness.
"Adam trained now the first real football session in Rome in the morning of the game. He looked good, that's OK,” Klopp said.
“I have no idea if we will use that or not [against Chelsea], I have to think about it. But that's good."
The Reds have had a busy few months, with their successful run in the Champions League meaning having to navigate two fixtures a week for the most part.
However, with just three games of the season remaining, the boss explained the rest of his side are fit, although the injuries sustained by some of his key players means he is unwilling to rotate his side.
"From [Wednesday night], all should be OK. It is the first game for weeks that nothing happened in the game," he said.
"You saw it is quite difficult (to rotate). We will see. We have to wait. But it's difficult, the whole situation is not too easy. But it would be much more difficult if we played tomorrow.
"The whole season is a constant challenge, we really fought so hard so far, now we have to finish the job.
"How could I pick different teams [for the Premier League and Champions League]? Not possible, they're both very, very important,” he said.
"I've said it a few times and I'll say it again. We have two semi-finals again, against Chelsea and Brighton, very important—no chance to think about anything else.
"Then after these two games we have two weeks to prepare for the other game. They're both exactly the same importance, absolutely no difference."
Joel Matip and Alex Oxlade-Chamberlain are the other current injury concerns for Jurgen Klopp, with the duo already being confirmed as being out for the rest of the season.