Call it a down year for the running back.
Just three players in the NFL -- LeSean McCoy, Adrian Peterson, and Marshawn Lynch -- have rushed for more than 400 yards through the first five games of the season, the fewest to do so since at least 2001.
Here's just a sampling of where Jackson ranks through Week 5:
Rushing yards: 309 (13th in NFL)
Yards per rush: 4.75 (12th in NFL)
Rushing touchdowns: 4 (tied-2nd in NFL)
Yards after contact per rush: 2.40 (2nd in NFL)
First downs per rushing attempt: 32.3 percent (4th in NFL)
Receiving yards: 153 (10th in NFL among running backs)
Rushing & receiving yards: 462 (15th in NFL among all players)
His 462 combined rushing and receiving yards puts him on track to have 1,478 yards on the season, which would eclipse his career high of 1,433 yards, set in 2009.
Jackson drew praise from his teammates last week when, on four days rest, he battled a sprained MCL to play in 50 offensive snaps in a loss to the Cleveland Browns. The Bills also got a boost in that game from C.J. Spiller, who was hobbled by ankle and quad injuries but still limped his way to a 54-yard touchdown run.
On the season, though, Jackson's steady performance has made up for what has been a slow start for Spiller. Here's a look at Spiller's numbers through five games, compared to last season:
Rushing yards: 296 (last season: 365)
Yards per rush: 4.0 (last season: 7.60, first in NFL)
Rushing touchdowns: 1 (last season: 3)
Yards after contact per rush: 1.11 (last season: 4.19, first in NFL)
First downs per rushing attempt: 10.8 percent (last season: 29.2 percent)
Receiving yards: 29 (last season: 119)
Rushing & receiving yards: 325 (last season: 484)