Linebacker Oren Burks suffers a knee injury in the first quarter. Before Friday's call, The Athletic reported that the injury was not considered serious.
Shanahan said Burks suffered a knee sprain but is expected to be ready for Week 1.
Linebacker Curtis Robinson left the game in the first quarter and was ruled "out." Shanahan revealed that he suffered a high-ankle sprain.
Defensive lineman Akeem Spence was examined for a concussion in the fourth quarter. Shanahan said the defender is in the concussion protocol.
"That's it from the game," the coach noted.
The 49ers will open the regular season on Sunday, September 11, against the Chicago Bears at Soldier Field.