He hasn't quite hit his stride yet in 2013. Foster has just two scores, 292 yards and an average 3.8 yards per carry. That YPC is the lowest of his career and he's never been below 4.1. Ben Tate is going to get 12-15 carries, according to coaches, so that could be something to watch for since Tate has just 34 carries on the season.
Fantasy impact: He has been a little disappointing this season since most fantasy owners spent a top-five pick on him. Things aren't going to get any easier against the 49ers either. Their D is a little banged up with Patrick Willis still not close to 100 percent and Aldon Smith having off-the-field issues. You're obviously going to play Foster, but your expectations shouldn't be high.