Goals from Ki Sung-yueng and Jonjo Shelvey sealed the win for Garry Monk’s side but United played well during the match and looked far more threatening than they had in recent games.
Prior to Shelvey’s winner, United put Swansea under a period of sustained pressure and were unlucky not to score when Marcos Rojo headed over from three yards.
Van Gaal said he couldn’t have asked for much more from his side but said they must convert their chances if they are to prosper this season.
Speaking about the result, van Gaal said: ”I will say to the players that I am very disappointed but in the process of development of our play it was a very good match.
“When you can play like this, so dominant and creating chances, you can hardly improve, only with scoring the goals.”
Robin van Persie, Wayne Rooney and Radamel Falcao continue to frustrate however and their indifferent form will be a cause for concern as United look to score the goals needed to qualify for the Champions League.