The 49ers announced they placed offensive lineman Ben Garland on injured reserve Tuesday.
Garland strained his calf after playing 66 of 73 snaps.
Richburg remains on the physically unable to perform list.
“Richburg, he had the knee from last year,” Shanahan said Monday, “and then he had shoulder surgery that happened during the offseason also. The shoulder surgery really set him back. I’m not sure which one has set him back the worst right now, but I know we’re not going to get him until at least Week 12.”
The 49ers also announced they officially added cornerback Parnell Motley on the active roster after he completed COVID-19 protocols and passed his physical.
The team waived tight end Daniel Helm.