As expected, neither linebacker Reuben Foster nor safety Eric Reid will play during the San Francisco 49ers' road game on Sunday against the Arizona Cardinals.
Foster is still recovering from a high-ankle sprain he suffered during Week 1 against the Carolina Panthers. Reid is recovering from a PCL injury he suffered during Week 2 against the Seattle Seahawks.
As for the three players who were in the concussion protocol this week, Shanahan said Friday that they would all be questionable for Sunday's game.
"When it comes to concussions, my experience with it is I don't ever try to totally predict," Shanahan said. "Things can change and you never totally know what to expect. And you've got to be very safe with that stuff also."
Running back Carlos is also questionable and will be a game-time decision.
"He got out there a little bit more today," Shanahan said. "Definitely still hurting."
Below are the official injury reports for the 49ers and the Cardinals. Also included are Friday's practice participation reports, which were provided by the 49ers Communications team.
San Francisco 49ers
Out
LB Reuben Foster (ankle), S Eric Reid (knee)
Questionable
LB Brock Coyle (concussion), RB Carlos Hyde (hip), RB Kyle Juszczyk (concussion), S Jaquiski Tartt (concussion), DE Pita Taumoepenu (ankle)
Arizona Cardinals
Out
G Alex Boone (chest), G Mike Iupati (tricep), DT Robert Nkemdiche (calf)
Questionable
WR John Brown (quadricep), T D.J. Humphries (knee), WR J.J. Nelson (hamstring)
San Francisco 49ers Friday Practice
Did Not Participate In Practice
LB Reuben Foster (ankle), S Eric Reid (knee)
Limited Participation in Practice
LB Brock Coyle (concussion), RB Carlos Hyde (hip), RB Kyle Juszczyk (concussion), S Jaquiski Tartt (concussion), DE Pita Taumoepenu (ankle)
Full Participation in Practice
T Joe Staley (not injury related)
Arizona Cardinals Friday Practice
Did Not Participate In Practice
G Alex Boone (chest), G Mike Iupati (tricep), DT Robert Nkemdiche (calf)
Limited Participation in Practice
WR John Brown (quadricep), T D.J. Humphries (knee), WR J.J. Nelson (hamstring)
Full Participation in Practice
LB Deone Bucannon (ankle), TE Jermaine Gresham (ribs), LB Chandler Jones (chest), T John Wetzel (biceps)