Despite taking the lead through the 22-year-old in the 10th minute, the French outfit suffered a 3-2 loss in Naples to remain pointless in Group F.
"We played well and that's why I'm disappointed because we could have won," UEFA.com quotes him as saying. "We made some silly mistakes.
"We've played big clubs like Arsenal and Dortmund and we hope we can play in this competition again next year. It's not over yet, though. We'll play to the very end because you never know what could happen.
"To have zero points after four games is a shame. There are lots of youngsters in the squad, me included, and we'll learn from this."
Marseille are currently at the foot of the group with no point from four matches.