The Niners offensive line may actually be worse than the Eagles line.
Frank Gore is only averaging 2.5 yards per carry and has not shown the same explosiveness as last year. His ankle injury may keep him out of Sunday's game, and even if he does play, making cuts on a bad ankle is extremely difficult.
If Gore is out, then the reins fall on rookie fourth-round pick Kendall Hunter, who is much like LeSean McCoy in that he is a very shifty runner who can make defenders look silly. Hunter, though, hasn't had much more success than Gore on the ground, as he is only averaging 2.7 yards per carry.
The Eagles should put eight in the box to make sure the run doesn't beat them because Alex Smith is surely not going to beat them.
The Niners offense goes through their running game and tight end Vernon Davis, so stopping half of the offense right there is a place to start.