The Brazil playmaker was hurt during a clash of legs with Adrian Mariappa in the early stages of the contest at Vicarage Road and had to be replaced by Adam Lallana, who himself was returning from a five-week injury absence.
Zlatan undergoes knee surgery
Coutinho was later seen with heavy strapping on his thigh as the Reds secured a vital three points in their top-four ambitions in the Premier League courtesy of a sublime Emre Can bicycle kick.
Speaking at a news conference after the game, Liverpool boss Klopp provided an update on Coutinho’s condition.
“He has a dead leg,” he said.
“Hopefully it’s not too serious but of course it’s really painful and there was no chance [he could continue].
“Everybody could see he tried hard, but no chance.”