Robbie Stockdale felt his Sunderland side were too naive in the 3-1 Checkatrade Trophy defeat to Scunthorpe United but refused to be too critical of the performance.
Sunderland Under-21s, which included first team pros Jack Rodwell, Adam Matthews, Donald Love and Lynden Gooch, fell behind to a third minute Kevin van Veen header.
Duane Holmes added a second in first half injury time before Rees Greenwood’s stunning goal halved the deficit only for sub Josh Morris to add a third late on.
Sunderland were comfortably beaten in the end in the opening group game but Stockdale thought his players deserved credit.
Stockdale said: “I have to say first half we played some really good stuff, got in some good areas, we didn’t shoot enough and our delivery could have been better but overall pleased with how we played - with a high tempo.
“It is about pitting our younger players against league players.
“I spoke to them before the game and said if they have aspirations of going out on loan then these are the type of games they will be judged.
“I thought they came out with credit. There was some naivety with the goals, James Talbot made a fantastic save but could we have been first to the rebound?
“The second one looked like Denver [Hume] just switched off. At 2-0 the next goal is always important. We were keen to stress that, when it came it was a great time for us.
“There was no way they wanted to lose that game. They were agitated when we were on top, it felt like a proper game.
“This is a fantastic learning curve for the players.” Sunderland U21s face Doncaster Rovers on October 3 before closing the group stages at Grimsby Town on November 8.