A brace from Jamie Vardy and a volley from Danny Drinkwater gave the Foxes all three points in a resurgent display in the wake of Claudio Ranieri’s dismissal last week.
And speaking at half-time, Carragher highlighted the Brazilian as a weak link within Klopp’s defensive setup.
The ex-Liverpool centre-back did, however, admit he sympathised with Lucas’ situation, conceding that his former team-mate should not be fielded in defence due to his inexperience.
“I have sympathy for Lucas, he isn’t a centre-back,” he explained on Sky Sports’ Monday Night Football.
“Lucas should never be playing there. He doesn’t have the skill-set for the position and he’ll always get found out there.”
Speaking after the match, Carragher compared Lucas being played at centre-back and being asked to track the pace of Vardy to him being asked to play right wing. “I feel sorry for him,” said Carragher.
Lucas had acquitted himself very well in his last outing at centre-back, in the 2-0 victory at home to Tottenham Hotspur, but Monday night’s trip to the East Midlands presented a completely different challenge.
While the No. 21 was able to nullify the more methodical Harry Kane at Anfield, the combination of Lucas and James Milner on the left-hand side of Klopp’s defence was no match for Vardy.
This should have been apparent from last season’s 2-0 loss at the King Power, when Vardy ran rampant, with his pace bamboozling the abject Dejan Lovren throughout.
Klopp seemingly acknowledged this at half-time, switching to a three-man defence, but the Reds fared little better, conceding another goal on the hour mark, with Vardy heading past Simon Mignolet.
Making Liverpool’s failing at the back more glaring was the standout performance of Mamadou Sakho on loan at Crystal Palace at the weekend.
The Frenchman, who was exiled by Klopp in the summer after a series of transgressions, would arguably have provided Joel Matip with the perfect partner.
Beyond Sakho, Klopp still had a more accomplished centre-back on the bench in Ragnar Klavan, having described the Estonian as “the type of person who is coming here to fight and to win” on his arrival in the summer.
Carragher was right to criticise Klopp’s defensive unit against the Foxes, with Lucas certainly no long-term solution alongside Matip.