The injury to Herrera leaves United with just Darren Fletcher, Tom Cleverley, Anderson and Nick Powell as the central midfield options.
There was always a risk that if Herrera was injured, United’s already weak midfield would be severely exposed and that may be the case now against Sunderland.
With every player fit, United’s midfield was poor in comparison to the biggest teams around the world but with so many injuries, it has become a parody of itself and is truly woeful.
In better news, Robin van Persie is fully fit and will be available for selection for the first time under Van Gaal.
The Dutchman has been working on regaining his match fitness following an extended holiday after the World Cup this summer and United missed his clinical touch up front against Swansea last week.
Van Persie may start up front or from the bench but having him back in the squad will be a real boost.