The 49ers had a mass exodus in the 2015 NFL offseason that were predominantly pretty important players. The retirement of star linebacker Patrick Willis still has NFL fans scratching their heads, and the same can be said for Chris Borland who was very early into his NFL career.
The 49ers also lost cornerbacks Chris Culliver and Perrish Cox. On the offensive side of the ball they were dealt some significant blows when running back Frank Gore left for Indianapolis, starting left guard Mike Iupati left for the Cardinals, and wide receiver Michael Crabtree left for the Raiders. The change however with the biggest impact probably goes to the departure of Jim Harbaugh. The 49ers former head coach accepted the Michigan head coaching job while Jim Tomsula was promoted to head coach by the organization. But 49ers fans things may not be as gloomy as previously thought.
The 49ers brought in wide receiver Torrey Smith who will make more of an impact than Crabtree ever did, running back Reggie Bush who might not be as durable as Frank Gore but is faster and more agile, Jerome Simpson who is a solid wide receiver with experience in this type of offense, and finally guard Erik Pears from the Bills. On the defensive side of the ball they added standout Cardinal Darnell Dockett, linebacker Philip Wheeler, and corner back Shareece Wright.
In the 2015 NFL draft the 49ers took defensive tackle Arik Armstead in the first round which when paired next to Darnell Dockett should make for a resounding force. With the 49ers 3rd round pick they took outside linebacker Eli Harold, who should help replace some of the production lost by the departure of Willis. In the 4th round they drafted running back Mike Davis to help add some depth to their running back stable.
Currently on the roster, NaVorro Bowman should be back to full health and replacing Patrick Willis on the inside, Aldon Smith will be generating a pass rush from the second level, Free Safety Eric Reid is as talented as they come, and nose tackle Glenn Dorsey should help solidify what is actually a very powerful defensive line.
On offense Iupati will be missed without question, but the 49ers should be able to protect Kaepernick pretty steadily. Carlos Hyde will be taking over the duties as lead running back but the 49ers should use Reggie Bush pretty effectively as a change of pace back.
On as for the wide receivers, the 49ers are better off than when they started in free agency; Anquan Boldin, Torrey Smith, Jerome Simpson, Vernon Davis (TE), and DeAndrew White are more targets than Kaepernick has had in his entire career. The 49ers may need to iron out a few wrinkles but for the most part they look ready to do battle in the NFC West.