Kasper Schmeichel insists Leicester must find their killer instinct after a shock defeat at Legia Warsaw.
The Foxes’ Europa League hopes suffered a potentially damaging blow with a 1-0 defeat in Poland on Thursday.
They are joint bottom of Group C with Napoli, who lost 3-2 at home to Spartak Moscow, with the pair having been pre-tournament favourites.
Legia top the group with six points after Mahir Emreli’s goal sunk Leicester and Schmeichel knows the Foxes, five points adrift of the leaders, need to improve.
“We started slow and finished better, but ultimately it’s very disappointing,” the goalkeeper told LCFC TV. “We gave ourselves a mountain to climb when we conceded.
“On a difficult European night, a difficult pitch, we created enough chances I think in the second half. Unfortunately, it took until half-time to get things right.
“I think in eight out of 10 games we’d get something out of the game with the amount of chances we created but we lacked that little bit of cutting edge today and we’re disappointed.
“We’ve got to do it the whole game and that’s the most important thing. For us, it’s a case of starting quicker. We’ve got to start quicker and we have to work with that.”
Leicester now go to Crystal Palace in the Premier League on Sunday able to recall Wilfred Ndidi after he was banned for the trip to Warsaw.
Kelechi Iheanacho is available having been unable to enter Poland due to a problem with his travel documents. Jonny Evans’ foot problems mean he remains a doubt with Wesley Fofana (broken leg) and James Justin (knee) out.
“It’s a big game for us at the weekend,” added boss Brendan Rodgers. “We’ll get back and recover tomorrow, put some preparation into the team and then we’ll be fresh and ready to go on Sunday.”