A lot can change in four years. Just ask Donny van de Beek after he sealed his long overdue exit from Manchester United. Ole Gunnar Solskjaer was still the manager. A front three of Marcus Rashford, Anthony Martial and Mason Greenwood was threatening to become the best in all of Europe. Juan Mata, Eric Bailly, Marcos Rojo, Odion Ighalo and Timothy Fosu-Mensah were all under contract. And Donny van de Beek, a £34 million signing from Erik ten Hag’s Ajax side, appeared on his way to ascending to the summit of European football after becoming that summer’s biggest signing at Manchester United. Fo…