Coming off a successful preseason opener at home against the Vikings last week, the San Francisco 49ers travel to Houston on Saturday for their first road game since the regular-season finale last year against St. Louis. Here are a few things to watch:
 
Alex Boone at RG: All signs point to Boone hanging onto starting RG despite the 49ers’ acquisition of Leonard Davis. Boone, who is switching inside from OT, played one series in the 49ers first preseason game against the Vikings, but should get more against the Texans. He wasn’t tested much in pass protection against the Vikings, so it would be beneficial for his evaluation if the team let QB Alex Smith and the first unit throw more.
 
First-team defense: The biggest surprise of the first game might have been the ease in which the Vikings moved the ball against the 49ers’ first-team defense. Blown coverage on the first series resulted in a 52-yard pass from Christian Ponder to Stephen Burton. Defensive coordinator Vic Fangio talked about that being the type of error the team needs to cleanup in the preseason.
 
Bahktiari and Haralson at OLB: With starting OLBs Aldon Smith and Ahmad Brooks expected to miss the game, Eric Bakhtiari and Parys Harlason are expected to start in their place. Harlson’s roster spot is essentially a sure thing, but Bahktiari is fighting for his NFL life. After jumping from practice squad to practice squad the past four years, the University of San Diego product is out of practice-squad eligibility. He needs to make the team’s 53-man roster to remain in the NFL.
 
Undrafted rookie WRs: Chris Owusu, Nathan Palmer and Brian Tyms have all had their moments throughout training camp, but with six obvious 53-man WRs on the roster, the trio of players are all working toward spots on the practice squad -- or another team’s 53-man roster. Owusu had the best showing in the 49ers first preseason game with three catches for a team-high 35 yards, but Palmer and Tyms have the ability to make a similar impact.
 
Does Moss get rolling? WR Randy Moss wasn’t targeted in the team’s first preseason game. Until he is, 49ers fans will be anxious to see what the 35-year-old has in the tank. If practice is any indication, it should be a lot. As the regular season inches closer, Moss is coming off arguably his best week of practice.
 
Johnson vs. Tolzien: The battle for the No. 3 QB job continues and Josh Johnson is expected to get an opportunity to show what he can do. Scott Tolzien is coming off a 10-for-13 performance and is in a good position to remain with the team. Johnson can’t squander this opportunity -- there aren’t too many left to show that he should be the No. 3 guy.

Follow 49ers reporter Kyle Bonagura on Twitter: @CBSSportsNFLSF and @KyleBonagura.

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