Sidelined Vikings running back Adrian Peterson, who is expected to be out for most if not all of the rest of this season, tweeted for the first time in two weeks Friday in a series of messages about racial injustice.

This comes on heels of activism around the league — and frank discussions about racial issues from his teammates as they head to Carolina this weekend.

Peterson tweeted twice about the sentencing disparities between blacks and whites, writing, "U.S. Sentencing Commission reported that BLACKS receive 10% longer sentences than whites through the federal system for the same crimes."

He also urged change in this country:

The series of tweets prompted the typical responses of both criticism and support. To one critic, Peterson responded: