DL Justin Smith, DL Will Tukuafu and TE Nate Byham are not in uniform for the 49ers' preseason game against Minnesota on Friday night. 

An All Pro at DE and DT last year, Smith isn't being subjected to any unnecessary rigors.

Byham missed all of last season with a torn ACL and recently missed two practices with soreness in his hamstring. Byham said the decision to sit out practice was precautionary, which is believed to be the case for the game, too.

The reason for Tukuafu's absence is unclear.

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