RB Carlos Hyde is also listed as questionable. He has been plagued by a foot injury over the past couple of weeks and has also been limited in practice.
On Sunday against the Ravens, Boldin had five receptions for 102 yards while Hyde had 55 yards on 21 carries.
San Francisco 49ers
Questionable: WR Anquan Boldin (hamstring), RB Carlos Hyde (foot), G Erik Pears (back)
Probable: G Alex Boone (shoulder), LB NaVorro Bowman (shoulder), LB Ahmad Brooks (shoulder), RB Reggie Bush (calf), TE Vernon Davis (knee), WR Bruce Ellington (calf), TE Vance McDonald (chest), S Eric Reid (chest), T Joe Staley (knee), G Brandon Thomas (ankle)
Seattle Seahawks
Out: CB Marcus Burley (hand), DT Jordan Hill (quadriceps), LB Nick Moody (ankle)
Questionable: DE Demarcus Dobbs (shoulder)
Probable: DE Cliff Avril (ankle), T Justin Britt (hip), S Kam Chancellor (shoulder), DE Frank Clark (hamstring), T Garry Gilliam (ankle), WR Tyler Lockett (hip), RB Marshawn Lynch (hamstring), CB Richard Sherman (ankle), CB Tye Smith (hip), LB Bobby Wagner (pectoral)