Assistant coach Francis Jeffers says Everton’s Under-23s learned a valuable lesson as they were beaten by Leicester City in the Premier League Cup on Monday night.
Despite the 2-1 defeat, the young Blues finished second to the Foxes in Group F - with both sides progressing to the last 16 of the competition.
David Unsworth fielded a side combining experienced heads at Under-23 level and youngsters making the step up from Under-18s, with the likes of Luke Garbutt and Beni Baningime playing alongside Anthony Gordon and Con Ouzounidis.
Everton looked to be heading for top spot when Alex Denny netted 20 minutes from time but two goals in the final five minutes from Kairo Edwards-John and Hamza Choudhury thwarted the Toffees.
And Jeffers says the late turnaround should serve as a reminder to the players about the dangers of switching off at the highest levels.
“It was an almost perfect performance for 84 minutes and I am so disappointed for the lads,” he said. “It is a big learning curve that you have to put in the performance for 94 minutes.
“To put it in for 84 minutes isn’t enough unfortunately. But we will learn from it, quickly.
“We were solid at the back for so long - exactly what you need to be to get a win away from home. But the ones where you concede so late, you have to man up, see it out and say, ‘a draw away from home isn’t a bad result’. Unfortunately, we let them get the second and that’s a disappointment.
“Any defeat is tough to take but when it happens like that in a near-perfect performance then it hurts a bit more, for sure.”
Everton's opener came after good work by Gordon down the left-hand side allowed Jose Baxter to tee up Denny, with the midfielder rifling his shot into the bottom corner.
The scorer joined Under-18s teammates Gordon and Ouzounidis in making the squad and Jeffers praised the contribution of those who stepped up at Holmes Park.
“I thought it was a great all-round goal by the lads,” he added. “Anthony Gordon did really well on the left with some great skill and we know he can do that, and we have to get him doing it more.
"Jose then did well to lay it off and it was a great finish by Alex.
“Con [Ouzounidis] did very well. He was aggressive, which is what you want from your centre-half, and, though the defeat hurts, all the young lads did well tonight I thought.”