Southampton midfielder James Ward-Prowse says becoming nastier has improved his form.
Two years on from his one and only senior cap in Germany, the 24-year-old midfielder was brought into the England squad on Monday after injuries took their toll on Gareth Southgate's squad.
Ward-Prowse said, "It is a good thing to be nice but to get to a certain level you have to have that bite and difference and ultimately, I want to play week in, week out and if the manager demands certain things of me, I have to abide by it and change my ways.
"I feel I have benefited as a person and as a player from those changes."
He added: "Since the new manager (Ralph Hasenhuttl) at Southampton came in, he mentioned a few things I needed to change, and I took that on board.
"I want to get away from that perception of the Southampton academy boy. That's not what I want to be anymore. That played a part in it for sure.
"A bit more aggressive, to try and stamp my authority a bit more on what's going on, so it was a good conversation I had, and I respected the way he approached me with that.
"I have utmost respect for him. He told me my strengths, my weaknesses and I feel I have benefited from that."