The 49ers placed Garland (calf) on injured reserve Tuesday.
Garland was the 49ers' interim center while Weston Richburg recovered from kneecap surgery, and now both will be sidelined. Richburg is eligible to return Week 7 against the Patriots, but it's unclear if that will happen. On the other hand, Garland can't return until Week 10 at the earliest. Hroniss Grasu is expected to start at center until one of the two gets healthy.