Van Dijk struggled throughout a hapless first half in west London, and with Liverpool going into the break two goals down, he was one of three players brought off.
When Van Dijk reemerged and took his place in the dugout there was strapping on his right leg, with Klopp providing an update after the game.
“Virgil felt the hamstring a little bit,” he told beIN SPORTS.
“He said he’s fine, but when I said we don’t take any risks, the physios were quite happy with that.
“I think it’s nothing serious, but that’s why we changed him.”
It is the latest in a long, long line of injury issues for Liverpool this season, which does not appear to be slowing down following the World Cup break.
Liverpool recently appointed Jonathan Power as their new club doctor, with the former Brentford matchday doctor due to begin his duties imminently.