The Young Lions booked a second successive appearance in a European Championship final with a 2-1 victory over the Netherlands on Wednesday (25.06.25) and the coach lamented that many of his players will be ineligible for the U21s after this weekend's showpiece against Germany.
Hailing two-goal hero Harvey Elliott, Carsley told Channel 4: "Harvey has been outstanding. He's one of many who has stood up. They're developing as a team and it's just a shame we only have one game left because I think this team is outstanding.
"Harvey and Charlie [Cresswell] didn't play a lot of minutes in the last campaign. We knew how important they'd be and they've taken that on board - the responsibility of driving the rest of the squad.
"They are two that have been in this position before and can help."
England overcame very hot conditions in Slovakia to reach the final and Carsley explained that his team had been training at the hottest point of the day in order to prepare for the situation.
The manager said: "We knew it was going to be very hot. We've done all of our training sessions in the hottest part of the day to prepare them for this kind of event.
"We've not hidden from the sun, we've exposed them to it, even to the point where we've given them opportunities to sunbathe after training and be exposed to the heat, and it definitely helps."
Elliott feels that England "deserve" to be in the final and is desperate to defend the crown that the Young Lions won in 2023.
The Liverpool star said: "It was amazing. A really tough game but to win is incredible. I can't put it into words. Another final but we need to rest, recover and go again because it's not over yet.
"Tonight was another amazing experience. Really tough conditions once again, but the way the lads dug deep, I think we deserved the final.
"It's one last push now and hopefully we can be crowned champions again."