The City youngsters put in a hugely encouraging display and were 3-1 up with less than five minutes to play thanks to goals from James McAtee (2) and Liam Delap when Derby staged a dramatic late fightback.
The Rams scored twice to claim a point with Delap also being dismissed for a second yellow card to compound City’s frustration.
It was tough on a youthful City but, as he reflected on the game, the new EDS boss said there were numerous positives to draw on and he backed his players to heed the lessons.
“It was a big shame as to be honest the lads deserved the three points,” declared Maresca.
“They put in a big effort, but it is something we need to learn. We have to manage some situations better.
“For me I don’t care about the age - they are good players and we can do good things.
“Like I say, I’m happy about the game - there are many things to improve but at same time for the effort it’s a shame for them.
“There were lots of excellent things to build on... all of them did a good game and many individuals gave a good performance.”
After having to spend a period in quarantine following his appointment, and so missing last Tuesday’s EFL Trophy win at Mansfield Town, Maresca was able to take charge on the touchline for the first time against Derby.
And he said he was eagerly looking forward to helping guide and mentor the players through the demands of the next nine months or so.
“Now it will be much better for me to be there working every day with them,” Maresca added.
“The work put in by the staff has been great while I have been in quarantine.
“Looking ahead, we know every week we have one or two games every week from now and that gives us the chance to improve and do things better.
“I will be there every day on the training every day with the players and I am looking forward to it and working with everyone.”