It would have been ridiculous to put Davies straight into England squad. He's not done enough to warrant it yet, he's only started like 10 or so games in his entire career !
Took Rooney about 30 odd matches before he got his first cap and he was a friggin worldbeater.
Surprised Davies was not in the U21's though, as he is at least (at the moment) a regular starter for a top-half-of-the-table Premier league club, whereas some of the U21's are either on loan at lower division clubs or nowhere near their parent club first-team. He was plucked from the U19s to train with the full squad last year, so thought they may look to move him up a level.