United's 100 per cent record fell by the wayside after a wasteful performance from Van Gaal's team.
United dominated the opening stages, making six attempts at goal in the first 20 minutes, but failed to capitalise on their dominance and left Old Trafford with one point, rather than three.
When asked after the match whether United's performance meant he needed to sign more forwards, the United manager said: "No, because we were three times the best team.
"My worry is that we have to dominate the opponent and we did it today, we did it against Aston Villa, Tottenham and (Club) Brugge.
"I am satisfied with the performance and not with the result and that is different.
"We were unlucky with rewarding ourselves because we have created a lot of chances."
The only big disappointment for Van Gaal was a refereeing decision that denied Wayne Rooney his first goal in 10 matches.
With just four minutes on the clock, Rooney raced on to Juan Mata's through-ball and lifted the ball over Tim Krul, but the goal was ruled out for a very marginal offside call.
Van Gaal said: "Wayne scored. Only it was not allowed.
"It is doubtful and the rules are that when it is doubtful, then do not flag.
"But it is also football and I have said already many times you need more equipment to help the referees and linesmen because it is not easy."