The Cardinals are 2.5-point favorites in the matchup.
Foster started the 49ers' season-opening matchup against the Carolina Panthers before leaving the game with a high-ankle sprain. He went on to miss the 49ers' next five games before returning for a Week 7 matchup against the Dallas Cowboys. Foster sustained a rib injury against Dallas and was inactive the following week against Philadelphia.
Foster practiced all week and head coach Kyle Shanahan was optimistic about his chances of playing against Arizona.
49ers defensive coordinator Robert Saleh said on Thursday that Foster has been unlucky with injuries during his rookie season.
"He's been very unlucky with the injuries that he's had," Saleh said. "He's definitely not injury-prone. That didn't even cross my mind. It's just been very unlucky and very unfortunate though, some of the things that have happened to him. Once he gets his body back, the improvement is just going to skyrocket. It's just a matter of getting him going."