Sore shoulder to keep Colin Kaepernick out of preseason opener

SANTA CLARA, Calif. -- In a move that comes as little surprise after he didn't throw in Thursday or Friday practices, the San Francisco 49ers announced Sunday afternoon that quarterback Colin Kaepernick will not play in Sunday's preseason opener against the Houston Texans.

Kaepernick has been battling a sore right shoulder, an issue that left him unable to throw in the team's final two practices of the week. On Friday, coach Chip Kelly and Kaepernick expressed some optimism that he'd be able to play but acknowledged that it would be a decision made closer to game time.

"His throwing shoulder, just from the accumulation of what we've been doing, is a little sore," Kelly said. "So, we're going to monitor that. He'll be limited (Friday) and hopefully we can get him to play on Sunday."

But the 49ers clearly don't want to push Kaepernick to play when they have an important week coming with joint practices and a preseason game against the Denver Broncos.

Kaepernick is still rebuilding arm endurance after an offseason in which he had to work his way back from shoulder, thumb and knee injuries. Kaepernick, a former high school pitcher, likened his shoulder issue to a pitcher having to bounce back after throwing a lot of pitches. Kelly said that Kaepernick and Blaine Gabbert have been throwing between 86 and 102 passes each day in practice.

"I think it's been the buildup," Kaepernick said. "It's something that you don't really get the reps of live action and that violent motion when you are practicing in the offseason. So I think it's just building my endurance in that area.

"I've experienced that a couple of times in my baseball career. My arm has always snapped back quick so (I'm) not too concerned about it."

With Kaepernick out, Gabbert will start at quarterback against the Texans. Gabbert took the bulk of the reps with the first-team offense in Thursday and Friday's practice.

Gabbert and Kaepernick are embroiled in a competition for the starting quarterback job.