The thing is you can never have a team of Rio Ferdinands and Rooneys throughout the team, you will inevitably fill it out with not so great players around them. Herrera has enough about him, in the defensive and attacking phases, to have a role especially under a manager that believes in him and he hasn't got that from Van Gaal. Granted he hasn't had a good season, I don't think anyone would dispute that, but still he has shown enough to be kept around and whether he starts or not will up to what the manager decides he needs and whether he takes his chance when it comes.