Belcher's a decent prospect playing what is the hardest position on the field to master. You make a mistake at full back, it invariably leads to a try.
I don't think he lacks commitment, just confidence really. I think he needs a sustained run of games in the first team to get that, he's not really had the chance to shine properly at first team level because of the injuries he's had. I think the try he got yesterday will do him the world of good.