Jurgen Klopp has admitted concerns over his defensive options, with Virgil van Dijk and Joe Gomez the only senior centre backs currently fit and available.
The Champions League finalists are due to play Torino in their final pre-season friendly on Tuesday before facing West Ham at home in their Premier League on Sunday.
Joel Matip (hip) and Ragnar Klavan (hamstring) missed Saturday's 5-0 thrashing of Italian side Napoli due to injuries and are doubtful for the Torino game at Anfield.
'Joel, we'll have to see. Klavan, shouldn't be too serious, but if Tuesday is too early I don't know yet,' Klopp told the Liverpool Echo.
'Maybe we will do some magic things with the formation on Tuesday. I don't know how we will do it.'
Croatia international Dejan Lovren will rejoin the squad on Monday after an extended break following the World Cup but is a doubt for the next two games.
Virgil van Dijk (top) and Joe Gomez (bottem) are the only senior centre backs fit and available
Joel Matip (top) and Ragnar Klavan (bottem) are both doubts for Tuesday's clash with Torino
Crotian star Dejan Lovren returns to the squad but is a doubt for the next two games
'Dejan didn't train so far. He probably won't play Tuesday and Sunday will be very difficult as well,' Klopp added.
'The first two league games at least are in the 'pre-season' (for the World Cup players).'
Liverpool finished fourth last season but enjoyed a fabulous run in the Champions League, making it to the final where they lost 3-1 to Real Madrid and in the process smashed the goal-scoring record of European football's elite competition.
Liverpool will face Italian side Torino in their final pre-season clash at Anfield on Tuesday
Klopp's men begin the new Premier League season at home on Sunday against West Ham
'The league will be difficult,' Klopp continued. 'It is not about judging our situation and thinking 'wow, really good'.
'We need to be ready each week, not only for a few games. That is our challenge.'
transfer window has been kind to Klopp as the new season approaches,
with the arrival of midfielders Naby Keita and Fabinho, while playmaker
Xherdan Shaqiri has arrived from Stoke and goalkeeper Alisson signed
from Roma in a world-record deal.