Brendan Rodgers admits it's a worrying sign for Leicester that Championship side Blackburn were "a lot better" than his team in their shock 2-1 FA Cup defeat.
Tyrhys Dolan and Sammie Szmodics capitalised on awful defending to earn Blackburn a 2-1 win as they reached a first FA Cup quarter-final for eight years.
Kelechi Iheanacho grabbed a second-half consolation but the error-prone Foxes got what they deserved against the Championship side.
Rodgers said: "Congratulations to Blackburn, they were the better team. We presented them with a couple of the goals, giving the ball away cheaply to concede for the first.
"Likewise with the second. We give it away and the player gets through the middle of our defence too easily and gets his finish.
"Then you're chasing it and 2-0 is not an easy scoreline to score freely in. We showed spirit and a drive but you have to show that when it's 0-0 and impose your game.
"We were unable to do that. It's consistency, it's mentality, an ambition and a drive to succeed and that's been too up and down for us. It doesn't help when you continually present opportunities to teams.
"Disappointed for the supporters, it's been a real challenge for them this season. The FA Cup was an opportunity for us to get to the quarter-finals, playing against a Championship team at home, but they were a lot better than us.
"We have to be worried about that."
Rodgers was without James Maddison and Youri Tielemans, with Maddison yet to recover from illness and Tielemans facing six weeks out with ligament damage to his ankle.
The Belgium international suffered an ankle injury after coming on as a substitute in the weekend defeat by Arsenal and missed Tuesday's FA Cup loss to Blackburn.
"Youri will be out for six weeks. Six weeks will feel like six months when you lose a player of that quality," Rodgers revealred.
"Sadly he's done the ligaments in his ankle. He won't be back before the international break."
Rodgers, who guided Leicester to a first FA Cup triumph in 2021, made six changes and insisted he should be the one in the firing line.
He added: "If there's anyone to blame it's me. I made the changes and sadly it didn't work.
"We brought four players into the starting line-up who won the FA Cup a couple of seasons ago, so the team should be strong enough and good enough.
"The FA Cup was a chance to get to a quarter-final, we were playing against a Championship team at home but they were better than us and we have to worry about that."
Blackburn boss Jon Dahl Tomasson said: "It was an unbelievable night for the club. The performance and result were well deserved. I asked the players to be brave on the ball.
"They followed the game plan perfectly. We were extremely brave, we were creating chances and out of possession we were extremely intense.
"We should have been out of sight before it got a bit nervous but the lads showed a lot of spirit, fighting when it was needed. The players have written another chapter in our great history.
"We are under construction. We have been inconsistent but in 2023 we have been consistent. The lads have done an excellent job.
"Now we are in the last eight in the greatest cup in the world. This cup is one of the only ones where it really is alive. We take the cup very seriously."
Leicester visit Southampton in the Premier League, live on Saturday Night Football; kick-off 5.30pm. Meanwhile, Blackburn are back in Championship action when they host Sheffield United on Saturday at 12.30pm, live on Sky Sports Football.
