Wayne Rooney stressed Manchester United's need to be more ruthless in front of goal after the 0-0 draw with PSV Eindhoven which left their chances of reaching the Champions League last 16 in the balance.
United, who would have sealed qualification for the next round with a win in the Group B contest at Old Trafford, endured a frustrating night as they saw plenty of possession but failed to convert any of the chances that came their way.
Although they have only lost one of their last eight games in all competitions, Louis van Gaal's men have scored just six times in that sequence and there has been continued criticism of their style of play.
And when asked after the PSV match if the team were ruthless enough, United captain Rooney told BT Sport: "No, we're not. I think we need to score more goals as a team.
"I feel we showed a lack of composure which put ourselves under pressure a lot of times.
"It's a learning curve for us, but we can't go on saying it's a learning curve. We have to start turning these games into victories."
Group B now has Wolfsburg top on nine points, United second on eight and PSV - who have the head-to-head advantage over the Red Devils, having beaten them 2-1 at home - third on seven, with one round of fixtures to go.
Those games see Van Gaal's men travel to Wolfsburg, while PSV host already-eliminated CSKA Moscow.
It means United need a win in Germany to guarantee progression, and Rooney added: "We're disappointed we didn't win this game.
"Going out to Germany is always tough, but we have to believe in ourselves and have the confidence in ourselves to do that.
"It's not the way we wanted it to be before tonight's game, but that's the way it is and we believe we're good enough to go out there and get the three points."
United boss Van Gaal concurred with Rooney, admitting he was worried about the team's goal rate.
Asked if he agreed with Rooney's comments about ruthlessness, Van Gaal said: "Yes, of course, because we are playing football to win - that is what he is saying, and I am saying that always.
"We have to win. But you cannot do it always.
"Of course I am worried (about the scoring rate) but I know also that goals are coming and going - it is not a consequence of good or bad performances.
"Today we could have scored at least three goals. They were not the most difficult chances but we didn't score. Then, the next game you can score out of nothing - that is football."
Van Gaal expressed his disappointment at the result, labelling his side's performance "average", and is in no doubt the assignment ahead in Germany is a tricky one that will require an improved display.
"The result is disappointing because I feel we could have finished this game several times," Van Gaal said.
"In the first half it was average and in the second half in spite of my changes it did not improve.
"Nevertheless, in the second half we gave only one chance away - so then you know at the end it is 0-0. That is disappointing, because we have to win in Wolfsburg.
"We are second so we are in the qualifying position, and we have to do it in Wolfsburg. But it is more difficult. It would have been much easier if we did it tonight."
He then sounded a note of optimism, as he added: "We have won already our home match against Wolfsburg (2-1 in September), so why can't we win in Wolfsburg?"
PSV coach Phillip Cocu was delighted with his side's efforts and felt United's confidence had drained as the contest went on.
Asked whether he thought United's style was boring, Cocu said: "I think they want to dominate the game.
"That is their style and in the first 20 minutes they showed a lot of power going forward and created some dangerous situations.
"But we felt as the game went on and they couldn't score a goal, they were not so dominant anymore.
"They couldn't find a solution of beating our defence. Tactically, we were very good.
"Maybe (in terms of) the confidence, they didn't believe any more in the last part of the game that they could win it."