Liverpool conceded early but bounced back to equalise through Mohamed Salah. They enjoyed almost 70% possession and had 10 shots on target but still they came away empty-handed as a 29-game unbeaten run at home was ended.
"It was a set-back, absolutely. I thought we had a really good start then conceded a freakish goal," Klopp told Sky Sports.
"We scored the equaliser, but for some reason it didn't give us the security back. We struggled to control the game and gave too many balls away," the German explained.
"The boys tried, we had good possession and had big chances but, in the end, if it is 1-1 and you defend the situation around the second goal like this, you leave everything open.
Klopp's side created a total of 22 scoring chances but injuries and illness have robbed them of key players, not least in attack where they are missing Diogo Jota.
"Harvey (Elliott) has been exceptional for us this season. He had a good start but couldn't keep it going. Thiago has been ill, up front the same (players) play all the time - they are the three strikers we have left," Klopp said glumly.
Liverpool have league games at Tottenham Hotspur and Southampton to come before next month's World Cup, which cannot come quickly enough as Klopp seeks to find some answers to his side's poor form in the top-flight.
"We had problems from the first day (of the season), injury wise. Players have had to play from the first day. It's our situation and it means we have to help ourselves, and that is what we will do," he said.
