The defender picked up the knock as the Reds prepared for the clash with the Seagulls at the Amex Stadium and required treatment from the club’s medical team.
Alexander-Arnold shook off the issue to take his place in the starting line-up and completed the entire 90 minutes as Liverpool extended their lead at the top of the Premier League table to seven points.
Asked what the injury was, Klopp told his post-match press conference: “I don’t know yet. It was the last situation in the warm up, I think he stepped on the ball – I didn’t see the situation, I only saw him going down.