Im not saying he will automatically plummet now but injuries(definitely knees) are a bad thing in the nba. Bigs with injury issues rarely pan out(see Oden) so if Noel falls(to like the third or fourth big taken as opposed to the first) it wouldn't shock me.
But hes not. X-ray were said to be negative and should be ready in 8months. If he do fall, it's not going to be all the way to 14. Maybe 5-7.