The Posh Under 18s were beaten 2-0 by Millwall on the opening day of the Professional Development League season.
With two under 15s in the starting line-up, Posh were competitive throughout, but were ultimately undone by a dubious goal via a deflection and a sloppy defensive mistake for the second.
Interim Lead Under 18s Coach Hugh Alban-Jones took positives from aspect of their display, but admitted they need to more clinical in front of goal.
"It was a cagy, competitive game, which you would probably expect on the opening day of the season. I don't think there was too much between the two teams, the first goal was a bit questionable because I am not too sure it crossed the line and then we could have done better with the second goal.
"We got into some good positions, but perhaps it was a day where we needed to be a bit more clinical in front of goal. We had two under 15s in the line-up, both did well, Cordell was lively on the wing and Aaron was strong at the back.
"The three substitutes that came on all provided a positive impact, we finished the game strongly so there are positives to take from aspects of the performance."
Posh: Bucknor, Bushell, Joseph, Christoudias (sub Chibuzo 80min), Arber, Sudakaran, Morgan-Antonio, Crozier (sub Jones 60min), Simmons, Mlityalwa (sub Norville 74min), Dagne. Unused subs: Al Sammour, Sango, Fraser.