Ralf Rangnick says Chris Armas has already been 'very helpful' as his assistant at Manchester United.
The American coach was brought to Old Trafford by the interim manager last month as part of his backroom staff following the sacking of Ole Gunnar Solskjaer.
Although they had never worked together, Rangnick knew of Armas from their previous roles as part of the Red Bull group, with the former having worked as both an assistant and head coach of the New York Red Bulls.
