Steve Stone bemoaned a costly second-half lapse as the Under-23s suffered a 2-1 defeat at West Bromwich Albion.
First-team men Grady Diangana and Callum Robinson scored the goals in a five-minute spell at the Hawthorns which lifted the Baggies off the foot of the PL2 Second Division table.
A fourth away defeat of the season denied the Clarets the chance to move into the third place and the play-off zone.
And Stone was frustrated at the manner of another narrow loss after his side dominated for long spells and almost rescued a point after Anthony Gomez-Mancini had pulled a goal back.
“It’s a really, really good experience for them again. It was a bit like when we went down to Selhurst Park a couple of weeks ago,” said the U23s’ boss.
“Crystal Palace had some (senior) players in the team and West Brom have done the same today with some first-team lads.
“It makes it a different game. That’s the type of game we want. We love that but what I don’t love is that we’ve been beaten in both of those games by the odd goal.
“We’re the wrong side of the margins and that’s not right.”
West Brom had four established senior players in their starting line-up, including the goalscorers and ‘over-age’ midfielders Jake Livermore and Romaine Sawyers.
But Burnley could still have led at half-time on the back of some solid defending and neat approach play and then almost repaired the damage of their poor start to the second half with an impressive late fightback.
“Against a really experienced side we dominated for long periods of the game and created chances with some really good play,” added Stone, who was disappointed to see defender Richard Nartey receive a late red card for apparently denying a goalscoring opportunity when Robinson still looked to have plenty to do.
“But for 10 minutes after half-time we decided to switch off and give the ball away and some individuals did what they wanted to do and not what we wanted to do as a team.
“That’s the most frustrating thing. It’s young men growing up and learning their profession, but they’ve got to learn quicker than that.
“I said to the boys at half-time there’s only one team that can lose this and it’s you, and that’s what we did for 10 minutes.
“We played some poor stuff and caused our own problems.
“Once you go 2-0 down against a professional football team, with the quality they had in, it makes it very difficult.
“It was a great response to get back in it and we showed real character to get back in but again, it comes down decision-making which wasn’t what we expect at this level.
“You can’t be giving that many simple passes away under pressure when it really matters.
“That’s what we’re looking at and putting pressure on these boys to make sure when they get around the first team that they can handle the pressure. And while most of them did, some of them didn’t.”