Stevenson missed Wednesday's practice due to an illness, Zack Cox of NESN.com reports.
As a result, Stevenson's status is worth monitoring in advance of Sunday's game against the Bills. Meanwhile, fellow running back Damien Harris (hamstring) logged a limited practice Wednesday after missing the Patriots' Week 15 loss to the Colts. If Stevenson and Harris are both available this weekend, the would likely settle back into a timeshare arrangement.