Liverpool are sweating over midfielder Lucas Leiva's hamstring injury that he sustained during Wednesday's 2-0 friendly win at Huddersfield Town.
Marko Grujic opened the scoring in the 31st minute before Alberto Moreno made sure of victory in the dying second of the game with Liverpool's second.
Lucas hobbled off in the 67th minute and was replaced by goalkeeper Shamal George, after Jurgen Klopp had used all his outfield substitutes.
George was deployed up front while Danny Ings switched to an unaccustomed midfield role, a situation that Klopp was not pleased about.
"In the first half we should have had a clearer lead," the German boss said.
"[In the] second half, after Lucas' injury, we had to fight and that's what they did. Of course it was not a normal pre-season game anymore.
"They [Huddersfield] changed a lot, they had two good teams.
"It was absolutely hard work but we could have scored more goals and maybe we should have scored more goals."