Boss Aidy Boothroyd insists England Under-21s must do some soul-searching after their heartbreaking early exit at Euro 2021.
Domagoj Bradaric's stoppage-time stunner dumped the Young Lions out of the tournament as they beat Croatia 2-1 but went out on goal difference.
Ebere Eze's penalty and Curtis Jones' second-half goal put England on the brink of an unlikely qualification in Koper.
But they were eliminated having needed to win by two goals and hope Portugal beat Switzerland. Jones was also sent off after the final whistle following scuffles with the celebrating Croatia team.
Portugal topped Group D after winning 3-0 and it is Croatia, rather than England, who will meet Spain in a quarter-final in May.
Boothroyd said: "It was a do-or-die effort and brilliant in many aspects, but we're bitterly disappointed and football is a cruel game.
"The young players will benefit in the long term but at the moment that sounds like a ridiculous thing to say.
"We didn't get knocked out today, we got knocked out against Switzerland (a 1-0 opening defeat). The way we played in the first two games is not a true reflection of who we are.
"I thought we played really well (against Croatia), I was proud of the performance and I'm as disappointed as the players are. They will learn from this. When you lose in the last minute of a game in a tournament it hurts and it's a lesson.
"We should look a bit closer at ourselves and examine where we can get better."
Boothroyd is out of contract in the summer and said he will continue to support senior boss Gareth Southgate.
"I'll carry on supporting Gareth as long as he needs me and carry on working with the development teams getting players through," he said.
"I'm confident I know what I'm doing for this job. The job is about producing players from 15 to 21 and up to the seniors. I can't do anything other than what I'm doing now, which is getting players through."
Jones had already hit the crossbar when Eze gave England a 12th-minute lead from the penalty spot after Eddie Nketiah had gone down easily under Bartol Franjic's challenge.
Croatia recovered, though, to wrestle control of the half and Dario Spikic fired over before goalkeeper Aaron Ramsdale denied Luka Ivanusec.
England improved again after the break and Dominik Kotarski saved Eze's free-kick and gathered Nketiah's shot after Eze slipped the Arsenal forward in.
Dwight McNeil's free-kick struck a post and Jones thought he had got the goal to send England through with 16 minutes left.
Rhian Brewster crossed for McNeil who held the ball up for the Liverpool midfielder to drill into the bottom corner.
But there was late drama when Lille left-back Bradaric rifled in from 20 yards in stoppage time.
Jones was then shown a second yellow card after the final whistle having become involved in a scuffle with the Croatia team.
Boothroyd added: "There was a team jumping around celebrating and it just got a bit fraught and emotions got a bit high. I haven't been able to speak to the referee. It's one of those highly emotive situations where difficult things can happen."
Goalkeeper Ramsdale also revealed his disappointment after his final game for the Young Lions.
He said: "Heartbreak, devastation, especially for me and the lads born in 1998, this is our last game for the Under-21s. It's tough to put into words.
"I haven't really spoken to anyone to be honest because it's an emotional time.
"We shouldn't have left it until the last game, it was in our hands and ultimately we blew it and not got the job done."