Coach Bobby Petrino said Monday that Johnson suffered a "bowel injury" during the 12th-ranked Razorbacks 31-7 win over Louisiana-Monroe on Saturday. He says there is no timetable for his return.
Johnson, a junior, was ninth in the Southeastern Conference in total offense last season with 111.2 yards per game. He is the school's all-time leader in kickoff returns with 1,936 yards.
This season, Johnson has 85 yards rushing on nine carries, including a team-best 49-yard run in a season-opening win over Tennessee Tech.