IIRC, the original window verbiage came from the saying "their window of opportunity is running out". See the Colts (Manning, James Harrison), see the yankees (Jeter, Posada, Rivera), see the Avalance (Borque), see the Sonics (payton and Kemp)....
this is where i recall the "window" verbiage starting. Now, that I think about this topic some more, and to keep on the Cliche topic....
So when a player is not doing well, the term announcers are using is he needs to get "UN tracked". Again, I think this is one announcers interpretation (how he heard it) turning the whole industry sideways. If a train is doing what they are supposed to be doing they are ON track. If they fail to do what they are supposed to be doing they become UN tracked. So, who and the heck was the first moron (I think it was James Brown CBS) who said he's got to get Un Tracked....LOL....NOOOO, he needs to get BACK ON THE FRIKIN TRACK as being UN tracked is causing all sorts of problems! I won't say Ebonics, but this is what I have ALWAYS thought when it came to this cliche.
Explain that one to me!