User blog comment:TenmaTsurugi/My Theory of Inazuma Eleven GO season 2/@comment-4091102-20120321200703

Yuuichi is younger than he was in the first GO season, so it might be that he didn't got injured at all. Because of the absense of soccer the training with his brother never took place and the accident did not happen. So he must still have trained somehow.

What I meant is that he has not RECOVERED, but instead WASN'T INJURED at all in the alternate timeline and came from a few years ago.