Man United progressed to the semi-finals of the Cup with a 2-1 win over West Ham United last time out but a poor run of results in the Premier League have left them fifth in the table, four points behind fourth-placed Manchester City.
Officials at Old Trafford are said to be alarmed with United’s league form and van Gaal will be let go even if he manages to win the Cup.
Jose Mourinho is widely considered to be the front-runner to replace van Gaal at United in the event of the Dutchman’s exit.
United suffered early exits in the Champions League and the Capital One Cup earlier this season and their league form has been awful, to say the least.
Van Gaal cannot expect to stay in a job given the poor football supporters have had to endure this term, even if he does end the season with silverware.