#3 Get Sergio Ramos to rough him up while on international duty
Sergio Ramos is a key figure in the Real Madrid dressing room.
It has been reported that he personally spoke to Cristiano Ronaldo to convince him to stay in Madrid when Paris Saint-Germain showed interest in the summer, and the club could again employ him to help them get the De Gea transfer up and running.
Ramos has been sent off 24 times in his career, including a record 19 times in La Liga. He has the tools to take care of himself and is certainly capable of causing harm if required.
So, next time the national team squad meet up, maybe Ramos could pull De Gea over to one side, pitch Real Madrid to him, and if the answer is negative, use other methods to "gently persuade" the goalkeeper to pack up his bags and head to the Spanish capital.