William Gallas is still tormented by Arsenal's UEFA Champions League exit to PSV Eindhoven and felt youthfulness was the reason behind the team's downfall.
The Gunners' final hope of a trophy this season disappeared last Wednesday after a 1-1 home draw to PSV took the Dutch club through 2-1 on aggregate.
Alex's own goal had put Arsenal in front before the Brazilian defender headed in a free-kick after a foul by Alexander Hleb.
Gallas felt it was a 'completely stupid' free-kick to give away and he remains bitter about the way The Gunners crashed out of Europe.
"Our exit was hard to stomach," Gallas told The Sun. "I think about it a lot.
"What made it even harder to swallow was I told my team-mates to be extra careful at set-pieces.
"We conceded the goal as the result of a completely stupid and needless foul. The ball was in the corner and all we needed to do was to wait. It was down to youthfulness.
"We lacked finishing skills. We created far more chances than PSV yet failed to convert a single one. We had to rely on Alex helping us out by scoring an own goal."
And Gallas concedes it will be difficult to be motivated for the rest of the season, with third spot in the Premiership the only target.
He added: "When you are a top-level footballer, victory is the only thing that counts. But there will be no trophy to lift.
"We will do all we can to finish third, but that is not the target you dream about.
"Everybody will motivate himself in his own way, but it is not going to be easy."
like i said earlier they gallas spoke as if he wants to leave arsenal when transfer windows are open. without him,arsenal will have no experienced defender...well except for king kolo