Louis van Gaal has said that Manchester United's second-half performance was not good enough in their 0-0 draw with PSV Eindhoven.
The Red Devils were left frustrated as they could not find a way past Jeroen Zoet and the game petered out to a goalless draw.
"We could have finished this game in the first half," Van Gaal told BT Sport after the final whistle.
"We were not playing in the second half [at] this level. We are waiting that we are scoring in the first half, but it doesn't happen."
Man United must now beat Wolfsburg in their final Champions League Group B game to ensure qualification for the knockout stage.
When asked how tough the game in Germany will be, Van Gaal said: "Very difficult, because I think Wolfsburg is the best team in our group.
"But [the win] is possible, we have won also at home. Also we are still second."
Man United must better PSV's final Group B result to be sure of reaching the last 16 of the competition.