Naby Keita is set to undergo a scan to determine the extent of the injury he sustained on international duty with Guinea.
The Liverpool midfielder sustained a hamstring problem during his country's 1-1 African Cup of Nations qualifying draw with Rwanda earlier this week.
Liverpool are unsure as to how long he will be out for, however, they expect him to miss this weekend's clash with Huddersfield Town.
It has been suggested that Keita trained alone before Guinea's first match against Rwanda last Friday - they played twice, with Guinea successful in their first meeting - as he was potentially managing an issue before the encounter.
While doubts persist over the fitness of the 23-year-old, who has played in all eight of the club's Premier League fixtures so far this season, Virgil van Dijk and James Milner will train ahead of the Reds' return to domestic action.
Sadio Mane may be risked, despite reportedly breaking his thumb while playing for Senegal. If he is to play, he will likely wear protective gear.
Mohamed Salah was also injured on international duty, as he was substituted during Egypt's win over Swaziland, during which he scored directly from a corner.
Klopp will be hopeful of having all five fit and ready as soon as possible as he gears up for a number of crunch fixtures in the coming weeks, including the Champions League double-header against Red Star and a Premier League clash away at Arsenal in early November.
Adam Lallana, Dejan Lovren, Fabinho and Xherdan Shaqiri are all fit, however.