Adrian Peterson’s back is tired from carrying the entire Minnesota Vikings team so far this season.  He injured his back in the Vikings week two win over the Detroit Lions but it won’t keep him out of the Vikings’ game Sunday against the San Francisco 49ers.  Peterson says the injury “is not a big deal.”  In two games so far this season Peterson has rushed for 272 yards on 40 carries (6.8 avg) and has four touchdowns.  That 6.8 yards per carry is pretty amazing and Peterson is probably the best player in the NFL right now, if you don’t believe me check out some of his highlights here: