The Liverpool midfielder had to be taken off in the first half of the Group E tie at Anfield, which the Reds went on to win 3-0 through goals from Mohamed Salah, Emre Can and Daniel Sturridge.
And Wijnaldum will need careful assessment as a result.
“Nobody spoke to me so far [about it]. At half-time I asked immediately and the ankle was already swollen. It’s probably not a good sign,” Jürgen Klopp explained after the final whistle.
“We saw a kick in the game and didn’t think it was too serious. Then it was swollen. We’re not sure if he twisted it or not. For sure, we have to make a scan.”