Jamie Carragher called for improvements to be made at both ends of the pitch after a defensive lapse cost Liverpool a result in Moscow against Anzhi Makhachkala on Thursday night.
Carragher pulled on the captain's armband in Steven Gerrard's absence and led the likes of Adam Morgan, Jon Flanagan and debutant Conor Coady out at the Lokomotiv Stadium.
And while he was proud of the performances of the youngsters who featured in the 1-0 loss, the veteran defender insisted the Reds must become more clinical in front of goal and in their defensive duties if they are to progress this season.
"We made a mistake just before half-time and at this level, when you're seconds away from the break, you cannot make mistakes like that," he said.
"We've got to be more clinical. And that's not just in relation to Thursday night and in the Europa League, it applies to the season overall.
"The loss to Anzhi was a big learning curve. Not just for the young players but for myself. That's European football for you though - you have to be very clinical at both ends of the pitch.
"But I thought we did okay. I thought the young lads did well. Anzhi are a team that has been assembled at quite a cost and they have a few top players in their side. So for the young players to come here and perform the way they did, I think we deserved something from the game."
The result alters the complexion of Group A and places the Reds in joint second place, level with Young Boys, a point behind Anzhi and two ahead of Udinese.
"We have got to make sure we win our home game against Young Boys," said Carragher. "If we do that, then that will put us in a great position [to qualify from the group] and then it will depend how Anzhi and Udinese do in their game.
"Ideally, we don't want to have to go to Udinese needing to win but if we have to go there to get a point I think we would certainly take [the draw] now."