Walcott has praised the "mental strength" of Gunners team-mate Jack Wilshere in returning to the England squad after his lengthy injury lay-off.
He said: "I think the way he's started after so long out for Arsenal is absolutely fantastic. You have to give him credit. He's worked so hard to get back fit.
"To come back into an England team at such a young age at a high standard shows how good he is. He is mentally strong as well.
"I play with him every week and see him in training too and he loves every minute of it, and he's only getting better.
"He's strong, he's very level-headed and he can look after himself so he will not look out of place at all."