Two goals from Jamie Vardy and long-range effort from Danny Drinkwater condemned Liverpool to a 3-1 defeat at the King Power Stadium, with Philippe Coutinho netting a consolation goal for the visitors.
The Reds have lost five of their last seven matches in all competitions and have picked up just six points in the league in the 2017 calendar year.
Former Liverpool striker John Aldridge told the Liverpool Echo that Klopp's side are being undone by a lack of powerful players that can counter physical teams in the bottom half of the league table.
"When you play in the Premier League, you have to be ready to come up against the teams that play and the teams that fight," he said. "And against the latter, Liverpool have been found out repeatedly.
"It's no coincidence that all of their league defeats have come against teams in the bottom half, who will be aggressive and get in our faces. We have had all season, but we haven't found a way to deal with that.
"To me, Jurgen Klopp needs to change his transfer policy this summer. He needs to go after players with the aggression, the physicality and the character to cope with these demands.
"He needs players who can fight when the going gets tough. We simply don't have enough of those type."
Aldridge said Liverpool needed to sign a powerful centre-forward in the mould of a Robert Lewandowski, Harry Kane or Zlatan Ibrahimovic, along with at least one midfielder and one centre-back.
"When a defence is under pressure, they need somebody up front who can hold the ball up, take a knock off a centre-half, flick a header on, run the channel and give you an outlet, someone who starts the fight from the front," the former Real Sociedad striker said.
"[Roberto] Firmino is a nice technical footballer, but he's not that kind of striker. It's not his game."