Note that rushing frequency doesn't mean a thing about how good they actually are at rushing. So he might catch up to some guys that he is not actually better than.
And tangledweb, he played way more than 8. Pierce started 3, Brink started 1, Elliott started 2, that gives Jyles 12 starts and considering injury fill-in time for Buck, the quarter + OT of filling in for Brink, and around a half of football missed due to injury himself, he probably played the equivalent of 13 games. Nowhere near a 1000 yard rushing threat.
His 9.1 average so far this year can't be used to argue anything because it's only two games. I saw a ton of him last year and both games this year - and I do like him quite a bit - I put him behind Durant, Burris, Lulay and Pierce. Not to say he isn't good, he's a very good rusher. He's 5th on my list but closer to #1 (Durant) than #6 (Ray/Calvillo/Glenn, take your pick really).