Colin Kaepernick played through a foot injury in 2013.
Kaepernick revealed to The Sacramento Bee this week that he suffered a chipped bone on his forefoot and a ruptured capsule in the ball of his foot when a Seahawks defender landed on it in a Week 2 loss at Seattle.
After rushing for 87 yards against the Seahawks, Kaepernick didn't clear 20 yards on the ground again for more than a month.
"I noticed it, especially in practice," Jim Harbaugh said in March of Kaepernick's limited mobility. "I think anytime you have a foot, a hand or a finger, it affects you throwing and running."