Colin Kaepernick won't play in the 49ers' preseason opener

Colin Kaepernick's 2016 debut will be on hold after the San Francisco 49ers announced that the quarterback will not play in Sunday's game against the Texans because of a sore shoulder.

Kaepernick has been battling tightness in his shoulder the past few days, opting not to throw in Thursday's and Friday's practices.

Kaepernick is trying to rebound after struggling in 2015, when he threw for 1,615 yards with six touchdowns and five interceptions before losing his starting job to Blaine Gabbert and then undergoing offseason surgeries on his shoulder, knee and thumb.

Many are curious to see how Kaepernick responds to Chip Kelly's up-tempo system and whether it can revitalize his career.