The 49ers entered the 2018 season with few questions about their starting defense despite being in the midst of a roster overhaul under coach Kyle Shanahan and general manager John Lynch.
Richard Sherman and Ahkello Witherspoon were the clear-cut starters at cornerback. Adrian Colbert and Jaquiski Tartt topped the depth chart at the safety spots. Rookie linebacker Fred Warner was poised to take over the starting job early in training camp.
But all that certainty didn’t yield the results the team was looking for. There’s a growing sense a lack of competition throughout the defense led to stagnation, and coordinator Robert Saleh’s unit struggled to build off the promising end to 2017.