The Dutchman has found himself under increasing scrutiny after a six-game winless run which has seen United exit the Champions League and fall nine points behind Barclays Premier League leaders Leicester.
Van Gaal walked out of his weekly press conference on Wednesday after accusing the media of trying to undermine him in his position as United manager.
Rumours have been circulating all week that he could lose his job, with former Chelsea boss Jose Mourinho now available and reportedly willing to take the United hot seat if the opportunity arises.
United travel to the Britannia Stadium on Saturday and Van Gaal knows they are under pressure to get a result.
"Yes, I think so because, when you have lost three times in a row, then you need a victory," Van Gaal said in an interview with MUTV.
"We have focused ourselves to do that, but it is not easy. Stoke City have won against Manchester City, for example, and it's a special ground. It is not easy with a lot of circumstances that are not suitable always to playing good football."
Despite their miserable form, United still boast the meanest defence in the division, with just 14 goals conceded this season.
Nike Women Soccer Cleats US8.5 "I cannot say too loudly that we have to improve our defensive organisation," Van Gaal added.
Women Soccer Cleats Online "It is true it is always better that we keep a clean sheet, but we have to attack also and finish our chances - that is important. There are a lot of aspects we have to improve.
"One month ago we were first in the Premier League. Everything has changed, but it's also possible to be, next month again, in the fighting position for a title. But we have to win first against Stoke City, that is the main focus."
United captain Wayne Rooney insists the players are fighting to ease the pressure on the manager and reverse the club's fortunes.
Adidas Women Soccer Cleats US6.5 "Obviously you have a lot of people talking about things they believe are happening but in reality a lot of people who are writing that stuff don't know what's happening," Rooney told Sky Sports News HQ.
"We're working hard and fighting for the manager to try to get results and turn the season around. It's important we all stick together."
United have not won since leaving Watford with three points on November 21, a result which took them to the Premier League summit.
Soccer Cleats For womens US8 Rooney admitted a nightmare month has left United short on belief ahead of the trip to Stoke and back-to-back home matches against Chelsea and Swansea.
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