Alisson had to come off in the 39th minute of the 4-1 win against the Canaries having gone down clutching his calf after slipping while playing a goal kick.
Jurgen Klopp admitted he faces a goalkeeping shortage if the Brazilian is ruled out for a lengthy period, and an initial assessment indicates the keeper could be out until the end of September with a torn calf, which would mean he would miss Liverpool's first Champions League game.
"It's the calf and that's it," the German said as he ruled the Brazilian out of facing Chelsea in the European Super Cup on Wednesday.
"He couldn't carry on, that's not a good sign, and we have to see. Wednesday he will not play. With all my experience I can say that already."