Bleacher Report has a free agent in mind that could give the 49ers a boost to their backfield as they try to get McCaffrey and Mason healthy for a postseason run. B/R floated the idea of the 49ers reuniting with Jerick McKinnon:

Jordan Mason was on the field with his teammates wearing a blue non-contact jersey during Monday's practice. This means Mason can run and cut and go through the motions of practice but no one can touch him.

Mason injured his shoulder in the second quarter of the 49ers’ Week 6 win over the Seattle Seahawks. He returned for the second half, but exited after aggravating the shoulder on the first play of the third quarter. He spent the remainder of the game on the sideline and head coach Kyle Shanahan didn’t have much information after the game.