One of the most bizarre aspects of the offseason voluntary workouts throughout the NFL is that teams from time to time affirmatively excuse certain players from taking part in those exercises.

But if the sessions are truly voluntary, why would an excuse be even necessary?

Most recently, the Vikings “excused” running back Adrian Peterson and quarterback Tarvaris Jackson from Wednesday’s practice, allowing Maurice Hicks and Gus Frerotte, respectively, extended opportunities to get comfortable in the Brad Childress version of the West Coast offense.

For Frerotte, who played for the Vikings in 2003 and 2004, only nine players remain on the roster from when he last wore purple.

Childress said he expects Peterson and Jackson to return on Thursday.

Also “excused” on Wednesday was linebacker Ben Leber, whose wife was giving birth to the couple’s first child.