An MRI has revealed the need for surgery on Nelson's non-throwing shoulder. The anticipated recovery time is 4-5 months.
"We will miss Riley's leadership, toughness and playmaking ability," BYU head coach Bronco Mendenhall said. "Unfortunately, injuries are part of football. Riley is a great young man and we will look forward to his return."
Nelson, from Logan, Utah, has started each of BYU's first three games while sharing time with true freshman quarterback Jake Heaps. Nelson has completed 20-of-40 passes for 205 yards and two touchdowns while adding 148 yards and one touchdown on 31 rushing attempts.
"It's never fun to be injured," Nelson said. "I'm getting it taken care of as soon as possible so I can start my recovery and be back to help the team in the future."