The Saracens wing, who did not play during the Six Nations, has scored 11 tries in the Heineken Cup this season.
The Harlequins and England scrum-half told Sky Sports News: "Chris was disappointed after missing out on the Six Nations and he's since shown what a wonderful player and finisher he is.
"Scoring 11 tries in the Heineken Cup this year is not a bad effort and he is pushing to get back in the England team.
"He's a true professional who did what you have to when you're not selected, which is to go away and try and prove people wrong. We have some brilliant wingers, but Chris is right up there at the moment."
England will tour New Zealand this summer.