The Seahawks are announcing their starting quarterback for their preseason opener.  Head coach Pete Carroll said Tuesday that Geno Smith will start Saturday afternoon's preseason game against the Steelers in Pittsburgh.  Smith had been listed as first-string QB in the team's unofficial depth chart, with Drew Lock being listed at backup.  Carroll confirmed Smith will start on Saturday.  In other team news, cornerback Artie Burns left Tuesday's practice with a groin injury.