Philippe Coutinho had to leave Liverpool's 1-0 win at Watford early in the first half on Monday night after picking up an injury, though he should not be sidelined for very long.
The Brazilian star collided with Adrian Mariappa in the fourth minute, with the Watford defender's knee making contact with Coutinho's right thigh.
Coutinho limped off the pitch, then briefly tried to return before the injury proved to be too much.
Adam Lallana, who had missed the last five games with an injury of his own, came on in his place.
After the game, Liverpool manager Jurgen Klopp said Coutinho had only suffered a "dead leg" and suggested he could be fit to face Southampton in Liverpool's next game on Sunday.
"He has a dead leg," Klopp said. "Hopefully it's not too serious, but of course it's really painful and no chance [to continue]. Everybody could see he tried hard, but no chance."
And Coutinho himself downplayed the injury, writing on Instragram: "It isn't serious."
A post shared by Philippe Coutinho (@phil.coutinho) on
Watford were also forced into an early change when Christian Kabasele came on for the injured Miguel Britos in the 19th minute.
Hornets boss Walter Mazzarri declined to comment on Britos' status after the game, but he said the defender's loss limited his options to put on another substitute for tired attackers in the second half.