Johnson (shoulder) went to the X-ray room after Sunday's 31-10 win over the Cowboys, Alaina Getzenberg of ESPN.com reports.

EDGE Analysis

Johnson was deemed questionable to return due to a shoulder injury in the second quarter but later checked back into the game. He finished with nine carries for 54 yards, as well as a four-yard catch on his only target. James Cook produced 221 scrimmage yards and two touchdowns, so Cook should continue to lead Buffalo's backfield in Week 16 against the Chargers regardless of what the X-rays on Johnson's shoulder show.