Welker caught a ball from Tom Brady in the flats and turned to deke a defender. But he appeared to twist his left leg and fell to the turf. He limped off the field.
According to ESPN's Mike Reiss, Welker was taped up on the sideline and the injury "doesn't appear serious."
Welker had six catches for 48 yards before he left the game. The Patriots were up 38-7 when Welker left the game in the fourth quarter. The Patriots drove down the field once Welker left, and Tom Brady found Rob Gronkowski in the end zone to push New England's lead to 45-7.
Welker, the Patriots' all-time leading receiver, has caught 54 passes for a league-leading 688 yards this season. He has two touchdowns.
Last season, Welker caught 122 passes for the Patriots. He hauled in 1,569 yards and nine touchdowns -- a career high.