Dejan Lovren will miss Liverpool's visit to Porto in the Champions League on Wednesday through illness.
The Reds travel to Portugal on Tuesday ahead of Wednesday night's return leg in Estadio Do Dragao with Jurgen Klopp's side in the driving seat, having won the Anfield clash 2-0 last week .
Lovren made his Reds return in last week's game after a three-month layoff with a hamstring injury before forming part of the substitutes' bench for Sunday's victory against Chelsea.
However, the Croatian defender was absent from Tuesday morning's session after succumbing to illness this week. It's been a difficult few months for Lovren who has seen much the campaign beset by injury problems.
The £20m centre-back returned from the World Cup with a stomach issue that kept him out of the side until the end of September, before suffering the hamstring injury at Wolves in the FA Cup on January 7.
Lovren lasted less than five minutes at Molineux in the 2-1 reverse and only returned to action in last Tuesday's win over the Portuguese at Anfield.
The injury problems, coupled with the good form of Joe Gomez and Joel Matip this season, have restricted Lovren to just 13 Liverpool starts this term for the Reds.
Captain Jordan Henderson trained after picking up a minor ankle knock against the Chelsea on Sunday. The Reds skipper, who was again impressive in a more advanced midfield role, was taken off on 77 minutes against the Londoners, but was part of the squad on Tuesday morning.
Meanwhile, Alex Oxlade-Chamberlain also missed Tuesday's session after his 45-minute cameo for the Under-23s on Sunday.
Oxlade-Chamberlain played the first half of the U23s' 6-0 hammering of Leicester as he took another sizable step on his road to recovery after a year out of action.
His recovery process is being carefully managed by the club's coaching staff and his absence on Tuesday is not due to any setback on the long-term knee injury sustained 12 months ago against Roma.
Gomez, who played an hour of Sunday's win at the King Power Stadium, was part of the pack at Melwood prior to their flight out to Portugal.
Seventeen-year-old Ki-Jana Hoever also trained alongside his more senior team-mates.
Trent Alexander-Arnold on the key to Liverpool's progressing into Champions League semi-final
Liverpool squad: Fabinho, Van Dijk, Wijnaldum, Milner, Keita, Firmino, Mane, Salah, Gomez, Alisson, Henderson, Sturridge, Moreno, Lallana, Mignolet, Shaqiri, Robertson, Origi, Matip, Kelleher, Alexander-Arnold.
