The Dutchman is not confident that he will be able to bolster his ranks.
While the club currently sit in a commanding position in the league - with only Manchester City and Leicester above them in the table - the team have been criticised at times for their slow, methodical style that has proven largely effective, but has failed to capture the imagination of supporters.
Unfortunately for fans hoping to see new faces arrive to encourage something of a change, van Gaal has suggested that it will be difficult to do business midway through the campaign.
"We are looking [at players for January] but as you know it is not so easy to buy players and in January it is more difficult. We are looking but it is not for sure," he said.
While United's defence have put last season's inconsistencies completely in the past - no side has conceded fewer goals than the Red Devils this term - there are concerns about their lack of depth up front, which has seen the side struggle to put games beyond doubt. Their top goalscorer in the league is currently Juan Mata, who has just four strikes to his name.
As difficult as it is to make signings in the winter window, van Gaal will know that it will greatly enhance United's chances of lifting the title if they can bring a marquee name to Old Trafford in January.