Foles has replaced starter Michael Vick for the past few games and is six inches taller than Vick, meaning that the ball comes at a different trajectory to the receivers.
Avant told NFL Network: "It's a slight adjustment, there's a height difference. Nick, he sees the field. And on some of the routes you normally don't get the ball on, guys are getting the ball on those.
"So it's different, from a preparation standpoint, from a mentality standpoint. You're always alive and that's what you want. Also, the ball's gonna come out quick as he can get it there."