Arsenal boss Arsene Wenger says the chopping and changing of Theo Walcott from the England squad to the U21s messed with the player's mind.
The Frenchman is convinced Walcott's confidence was hit for six over the summer.
Wenger said: "It's very important for a player to know where he is.
"And when he goes to national teams and he is moved up and down, he gets uncertain and insecure and you lose him at both levels.
"When you are a football player, you want to know you belong here.
"And once you have made that step, and then you have to go back, you question yourself. And basically, that is what happened to Theo."
