Manchester United manager Louis van Gaal has admitted that he is concerned by the lack of goals scored by his side in recent weeks after the 0-0 draw with Crystal Palace on Saturday.

The stalemate was United's third goalless draw in the last three matches after scoreless affairs against local rivals Manchester City and Middlesbrough in the League Cup fourth round, which they went on to lose on penalties.

Van Gaal praised Alan Pardew's side for making it difficult for the Red Devils to create chances, but acknowledged that his side need to find more of a cutting edge if they are to climb the table.

"Palace showed a lot of aggression, they won every ball in the first quarter of the first half – the second and third ball was always for Crystal Palace, so they built up a lot of pressure on us," he told MUTV.

"In the second half, we could not develop our positional game and could not keep the ball, so we could not create too many chances. Of course [the lack of goals] is a concern. I said that after the match against Middlesbrough, when we created a lot of chances. You have to finish the chances. In the last minute of the first half, Ander Herrera could have finished it but he didn't. I asked him and he didn't know why, so that is a pity.

"But I can't complain about the result because I don't think we were the better team today. I cannot do anything anymore because we cannot train: we can only recover and recover. I am not happy because if you want to be the champions, you have to win these kinds of matches."

The draw saw United slip to fourth in the Premier League table ahead of their Champions League clash with CSKA Moscow in midweek.