Thiago Alcantara and Stefan Bajcetic will miss Liverpool's tour to the Far East as they continue their return to fitness.
And Nat Phillips and Conor Bradley are also notable exceptions from the 27-man squad that flew out to Singapore on Thursday afternoon.
The absence of midfield duo Thiago and Bacjetic must cast doubt over their availability for the start of the Premier League season at Chelsea on August 13 with neither have played a minute since their previous seasons were ended early through injury.
The pair will remain on Merseyside to work on their individual fitness programmes.
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Phillips - a transfer target for several clubs - hasn't taken part in full training this season while Bradley started both friendlies in Germany against Karlsruher SC and Greuther Furth. The Northern Ireland international, who excelled on loan at Bolton Wanderers last season, has been linked with another temporary move.
While in Singapore, Jürgen Klopp’s side will take on Leicester City on Sunday and Bayern Munich the following Wednesday before they return to Merseyside.
Young goalkeepers Marcelo Pitaluga and Viteszlav Jaros are the only other players who travelled back from the training camp in Germany on Monday not to make the trip to the Far East.
LIVERPOOL SQUAD FOR SINGAPORE: Alisson, Gomez, Van Dijk, Konate, Diaz, Szoboszlai, Nunez, Mac Allister, Salah, Adrian, Jones, Gakpo, Elliott, Jota, Tsimikas, Robertson, Matip, Clark, Scanlon, Doak, McConnell, Kelleher, Alexander-Arnold, Koumas, Quansah, Mrozek, Frauendorf.
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