The Reds are now without five first-team stars ahead of their clash with Real Madrid.
Anfield will host the Champions League clash in a repeat of the 2018 final.
According to The Times, though, Tsimikas will not be involved after picking up an ankle injury in training.
The report adds that the the Greek defender faces a short spell on the sidelines.
It comes after Jamie Redknapp suggested Liverpool have a fully fit squad following their win at Southampton.
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Speaking on Sky Sports, he explained: "Who knows, Liverpool might get an injury. They might have to suffer for a little while."
Reds fans have hit back, though, with one commenting: "Do Alisson, Elliott, Jota, Chiesa and Trent all play f****** tennis or what? Or do injuries only count if they are called Rodri or Odegaard?"
Another added: "Liverpool might get an injury to their starting goalkeeper, right-back or centre forward that could really hinder th… oh."
A third supporter also wrote: "Injury crisis but Liverpool haven't said a word."
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Meanwhile, one rival fan said: "Quite incredible how different their situation is being treated to Arsenal's. They've had one big injury."
Tsimikas' injury blow adds to the existing absences of Trent Alexander-Arnold, Diogo Jota, Alisson and Federico Chiesa.
Alexander-Arnold and Alisson are both out with hamstring injuries, although the former could return against Manchester City this weekend.
The right-back returned to team training on Tuesday, but Wednesday's clash with Real Madrid could come too soon.
Neither Jota or Chiesa are expected to make their comebacks this month, though.
Arne Slot has also only just welcomed back Harvey Elliott from a broken foot.
The 21-year-old missed 15 matches before being named on the bench against the Saints on Sunday.
As for Liverpool's title rivals, City midfielder Rodri has been ruled out for the season after tearing his anterior cruciate ligament.
Arsenal captain Martin Odegaard, meanwhile, missed two months with an ankle issue but returned to action earlier in November.
Despite their injury woes, Slot's side are currently eight points clear at the top of the Premier League.
The Reds have also won each of their opening four matches in the Champions League so far this term.
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