London, Nov 1: Louis van Gaal showed his concern at Manchester United's continued failings in front of goal as he warned his side must end their drought against CSKA Moscow next week.
United failed to score for a third successive game when they played out a scoreless draw against Crystal Palace at Selhurst Park on Saturday.
Van Gaal admitted his side were second best and insists they must bounce back when they resume their Champions League campaign at Old Trafford on Tuesday.
"Of course I am concerned (about the lack of goals), but today when you are not creating so many chances I cannot complain," he said.
"Nevertheless we had chances which we could finish and then you win this game. And that is our history until now. So we have to improve that."
Van Gaal denied the current run was affecting the mentality of his players.
"I cannot see that. I don't think so. I don't think they doubt their quality," he said.
"It can change in one match and let it be against CSKA because we need a victory.
"We have to hope we score against Moscow, because then we are talking in a different way."
The former Bayern Munich and Barcelona manager used Wayne Rooney in the central striker role with Anthony Martial operating on the left.
Rooney had just one clear chance to score and van Gaal switched the two players in the second half, but conceded he remains uncertain where Martial's best position is.
"We don't know yet. He always played as at left winger at Monaco," van Gaal said.
"I have to decide every week, depending on the game plan and the opponents.
"We have played with him in the striker position. It wasn't the first time for him but in Monaco he played almost always on the left." AFP