Salah continued his remarkable form so far this season with a match-winning brace against Leicester City this afternoon, taking his tally of goals for the season up to a club record-equalling 23 before the New Year.
However, the Egypt international was withdrawn in the 83rd minute of the victory at Anfield, and Klopp revealed after the match that Salah had picked up an injury.
"I don't know exactly [what the problem is]. He was limping and that's never a good sign," he told reporters.
"We will have to see what the problem is and what he can do for the next game."
Salah is the first Liverpool player to score 23 goals before the turn of the year in a season since Roger Hunt in 1961.