By Wilton Jackson The league’s designated rookie rule will not allow Brookyln to go after some players in a trade package for Durant. Since Kevin Durant requested a trade from the Nets on Thursday, his business manager, Rich Kleiman, has been working with Nets general manager Sean Marks to secure a trade. While “more than half of the league” has strived to put together trade packages and has contacted Brooklyn regarding Durant’s services, it could be very difficult for Brooklyn to deal the 12-time All-Star. Sports Illustrated’s Chris Mannix reported that Brooklyn has a “steep asking price” for…