SANTA CLARA — The 49ers just sent out their depth chart for Saturday’s exhibition game against the Houston Texans, and there are some changes in the secondary.

Dashon Goldson is officially the starting free safety while Reggie Smith is injured. Madieu Williams is officially second-string.

Shawntae Spencer is still the starting right cornerback even though he’s injured. Tarell Brown is his backup, and Tramaine Brock is third-string.

Chris Culliver is Carlos Rogers’ backup at left cornerback, while Phillip Adams is third-string on the left side.

This means Harbaugh’s staff likes Goldson and Brown and Culliver. It also means that Brown is in the lead for the nickel corner job, and if Spencer misses an extended period of time with his hamstring injury, Brown is next in line to take his starting spot.

Brown struggled in practice last week, but outplayed Tramaine Brock in Saturday’s game against the Raiders, and now he’s clearly “arrow up” in the mind of Harbaugh.

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