Van Gaal conceded that he was involved in a “rat race” with four other Premier League teams for the final two Champions League spots ahead of Saturday’s visit of Sunderland to Old Trafford.
While the Gunners, United, Southampton, Tottenham and Liverpool scrap for third and fourth, Chelsea and City have pulled clear.
Chelsea forward Diego Costa and City marksman Sergio Aguero top the Premier League scoring charts with 17 goals each.
United have netted just 10 more goals than the combined efforts of Costa and Aguero thanks to a poor showing from Robin van Persie (10), Wayne Rooney (nine) and worst of all, Radamel Falcao, who has scored just four league goals since his costly deadline-day loan move from Monaco.
“It is true because I cannot deny it,” the United manager said when asked if the lack of a prolific scorer had hindered his team this year.
“Robin van Persie cannot deny it, Falcao cannot deny it and Rooney – but he is not playing there so much any more.
“But we cannot deny that at this moment we don’t have a striker who scores 20 goals in the season.”
A lack of goals from his frontmen does not mean Van Gaal is certain to sign a new striker in the summer, though.
The Dutchman has faith in 19-year-old James Wilson and also has other priorities – like signing a dynamic, world-class midfielder.
“This doesn’t tell anything about next year,” van Gaal said regarding the future of his strike-force.
“They can be having an unlucky year and I have to take account with these aspects and I have to decide, with my staff, if it is these aspects or other aspects.”
And the Dutchman admitted record ??59.7million signing Angel Di Maria and his team-mates have struggled to adapt to his??much-publicised “philosophy”, which involves footballers playing with their??heads rather than their hearts.
“I think not only Di Maria, I think all the players (have),” Van Gaal added. “Because my belief, and also the belief of the board, is when you do things with your conscience then it shall be better.
“He needs to go through that process and at the end he shall be much better. He needs to do also things with his brain and that is a learning process, not only with Di Maria but with all the players.”