The 19-year-old left the Emirates on crutches in a protective boot having twisted it during a clearance in the first half.
Shaw suffered a hamstring injury earlier this season and also had a groin problem during the international break so this is the latest setback in what has been a frustrating start to his career at United.
Despite the fresh injury, Van Gaal feels he made the right decision to start Shaw: “I am convinced that I made the right decision.
“This is the life of a manager, the result is always giving you the reason or not [to pick these players]. I cannot do other things because I don’t have so many players.
“Shaw has come back from internationals not fit enough so we made him fit, but then he gets injured again. Then I have to give Young a game but Young is not fit enough to play 90 minutes. I have said this before. Then I have to change the line-up again.”
Shaw’s injury was an unfortunate accident but it doesn’t make it any less of a blow because he was really coming into good form having had to endure a slow start at United thanks to his hamstring injury.
At this stage there is no confirmation as to the extent of Shaw’s injury but he’ll more than likely miss United’s trip to Hull this weekend at the very least.