Three things: Vikings-49ers

Three things to watch for Friday in the San Francisco 49ers' preseason opener against the Minnesota Vikings at 9 p.m. ET:

1. Pass protection: Alex Smith took a pounding in the 49ers' exhibition opener at New Orleans a year ago. The takeaway, according to comments Smith made to reporters this week: "For sure, wear your mouthpiece in the preseason. That was a bad decision last year. Be ready for anything, it's football. The whistle blows out here at practice and as quarterbacks, you don't get touched. This is real ball and it's been, for all of us, a while since we’ve had that, and it'll be fun." It'll be much funner for Smith if his protection holds up. We should watch for signs of improvement at right guard, where Alex Boone and veteran Leonard Davis represent a fresh start. The Vikings were not a big team for preseason sacks last year. They had seven, tied for 24th in the league.

2. New life at running back: Veteran starter Frank Gore carried only four times in the 2011 preseason opener and eight times overall in four exhibitions. There's no reason to get him extended work at this point. Rookie second-round choice LaMichael James was an exciting talent with breakaway ability at the University of Oregon. He was ill and missed practice recently, but has since returned and should play quite a bit against the Vikings. Kendall Hunter and Brandon Jacobs are also competing for expanded roles in the regular-season rotation. Can Hunter build on a strong camp?

3. Backup QB race: Colin Kaepernick and Josh Johnson are battling for the right to serve in the No. 2 role behind Smith. A year ago, the lockout gave Kaepernick and other rookies very little prep time before the exhibition schedule. Kaepernick has subsequently had a full season to learn the offense. He'll be in better position to succeed. However, Johnson's roots in coach Jim Harbaugh's system run deeper. He played for Harbaugh at the University of San Diego, then signed with the 49ers in free agency this year.