This week, NFC West colleague Mike Sando posted the NFL's little-known rules for rookie participation in offseason programs. The key portion for our consumption: Draft picks and college free agents can't participate in organized team activities until after final exams at their respective schools.

That isn't an issue on most campuses, where finals occur in early May. But there are at least four NFC North players, all from Pac-12 schools, who apparently will miss all or most of their team's OTAs this spring because of a later academic calendar.

Atop the list is Chicago Bears first-round draft pick Kyle Long of Oregon, a guard who figures to compete for an immediate starting job. The Bears' OTAs will take place between May 13 and June 6, but Oregon's final exams don't end until June 14. Long is eligible for this weekend's rookie minicamp but not the Bears' veteran mandatory minicamp June 11-13. (*Update: An earlier version of this post said Long was eligible for veteran mandatory minicamp. Upon review, that is not the case.)

The same is believed to be true for a trio of UCLA players who were drafted by NFC North teams. Green Bay Packers running back Johnathan Franklin, along with Minnesota Vikings punter Jeff Locke and Jeff Baca, appear ineligible for OTAs until after June 14. The Packers and Vikings are both scheduled to have OTAs wrap up on the same day.

Franklin would not be eligible for the Packers' veteran mandatory minicamp, which is scheduled for June 4-6. Locke and Baca would be able to participate because the Vikings' mandatory minicamp is scheduled to start June 18. (Update: Frankin's eligibility status has also been revised.) Packers defensive end Datone Jones, also of UCLA, is eligible for OTAs because he has already graduated from school.

How critical will these absences be? Repetitions are the key to learning, but most rookies are swimming when they arrive at training camp regardless of their offseason participation. But in Long's case, for one, it stiffens the learning curve required for him to compete effectively for a Week 1 starting job, as many have projected he will.