How long before a jersey is released?

It seems strange to me, that there are more Nick Mangold jerseys than Muhammad Wilkerson ones. At least there should be a limited jersey for Wilkerson, and should really have an elite.

Back in the Reebok days they used to keep blanks back to customise to popular players or those players who have a breakout season. I would have thought that Nike would do the same, but I suppose they are happy to let customers go down the custom jersey route, for more money of course.