Mayock: Alshon Jeffery not worth a first-round pick

South Carolina wide receiver Alshon Jeffery was considered a potential top-five pick entering the 2011 college season after an 88-catch, 1,517-yard, nine-touchdown sophomore year. Jeffery’s stats fell to 49 receptions, 762 yards, and eight scores as a junior, and he declared for the draft on January 5. Jeffery’s supporters cited quarterback musical chairs and defense’s…