TEMPE, Ariz. -- Arizona Cardinals coach Bruce Arians says starting left guard Mike Iupati will have to undergo surgery to remove a bone spur in his triceps area and is expected to be sidelined at least eight weeks.

Arians says Iupati has been trying to play through the injury but the spur has broken off and is cutting into a tendon. The coach says it needs to be repaired before the tendon is cut in half.

Arians also says defensive tackle Robert Nkemdiche will miss Sunday's game with San Francisco after reinjuring a calf in practice on Thursday.

Guard Alex Boone is out for the 49ers game with a pectoral injury.

Inside linebacker Deone Bucannon (ankle) will play for the first time this season and wide receiver John Brown (quadriceps) also is expected back.

Starting left tackle D.J. Humphries (knee) is a game-time decision.