Germany's Instagram account showed off Muller writing his letter and sent a message to the England skipper: "Hey England. What‘s up Harry Kane? ✌️ We just finished our 5 days in your future team basecamp here in Thuringia 🇩🇪 Great conditions, very friendly people, and sometimes it‘s even raining 🌧️ Sounds perfect, right? 😉 Have a good time here in Germany! See you at the Euros! 😎"