The question comes into great focus after Kaepernick sat out of practice on Friday for a second consecutive day. As a result, Gabbert took all the first-team reps in a joint practice against the Texans.
Chip Kelly said Kaepernick was dealing with soreness on his surgically-repaired left, non-throwing shoulder.
"Hopefully we can get him to play on Sunday," the 49ers coach said.
Kaepernick remained hopeful he could see the field on Sunday. In the meantime, he mirrored Gabbert and San Francisco's other quarterbacks, going through his footwork and reads during the joint practice. The sixth-year pro said he was experiencing tightness in his arm, so he's being proactive about icing his shoulder and being cautious.