Arsenal under-21s head coach David Horseman shared his thoughts following our narrow 4-3 defeat away to Exeter City in the Vertu Motors Trophy.
Despite taking the lead three times through Charles Sagoe Jr, Harrison Dudziak and Osman Kamara, the Grecians fought back on each occasion before grabbing a late winner to take all three points.
Reflecting on the result, Horseman felt it was a missed opportunity to seal qualification for the knockout stage.
"Yeah, it was probably a rollercoaster of emotions. There was so much that was really good, but as has been the case in a few of our games recently, we've let it slip. To concede four goals, from our point of view, just isn't good enough. I've told the players straight that we should already be through in this competition.
"We should be through in the UEFA Youth League as well, but you can't be conceding goals like that, not at a club that prides itself on defensive discipline, and expect to win games. It's a harsh lesson, but one that's really valuable for their development. They just need to learn quickly because we're trying to help these young players build strong careers."
While disappointed with the defending, Horseman highlighted plenty of positives in attack.
"When the emotion settles tomorrow, we'll look back and see there was a lot of good stuff, probably 80% of what we did was really positive. But that remaining 20% let us down.
"There were some excellent attacking performances. Ceadach O'Neill led the line brilliantly, Charles Sagoe Jr caused them real problems all night, and Osman Kamara was a real threat down the right-hand side. We had so many good moments, which makes it all the more frustrating.
"The players will have learned a lot tonight, and hopefully they take those lessons on board quickly. We're in a group we believe we should be progressing from, so hopefully we can put things right and get the three points at Cardiff in our final fixture."
Horseman also praised the travelling Arsenal supporters who made the trip to Devon.
"Playing in front of such a crowd and seeing so many Arsenal fans here was a great experience for the players. I have to say, this was the first time in the Vertu Trophy that it really felt like a proper game - and that was down to our supporters.
"They brought fantastic energy and noise, and the players really appreciated it. I'm sure the fans could see there's a lot to be excited about with this next generation of Academy players.
"It just shows what a big club this is - to bring that many away supporters all the way from London. The staff and players are really grateful for that support."