The fly-half told BBC Sport: "Chris burst onto the scene and had the ability to pop up anywhere, but teams picked up on that. But like a frustrated goalscorer, he'll get one try, then two, and suddenly he'll feel very happy.
"When people realise what you're doing and they spend time on the video trying to work you out, life becomes harder. That's part of the reason why now he's a little bit frustrated he can't find the same space.
"Chris is dealing with that really well. I know there's been a lot of stuff thrown at him in terms of press and public viewpoints. But for us he's still a lethal finisher and a guy who can break open a game. We've got utmost faith in him."
England face Italy at Twickenham this afternoon.