Three things: 49ers-Chiefs

Three things to watch for Friday night in the San Francisco 49ers' second exhibition game of the 2013 season, set for 8 p.m. ET at Arrowhead Stadium:

1. QB comparison. Former teammates Alex Smith and Colin Kaepernick have competed before, but never on opposite teams. That changes in this game. We're past analyzing the 49ers' switch from Smith to Kaepernick last season. The quarterback comparison in this matchup is for fun, nothing more. Will the 49ers sack Smith or pick him off?

2. Jenkins and WRs. The 49ers would like one of their receivers to step forward as a worthy starter opposite Anquan Boldin in two-receiver personnel groupings. A.J. Jenkins' speed, overall potential and 2012 first-round draft status make him the player San Francisco wants to see emerge above the others. It hasn't happened yet. Jenkins was hurt early in camp. He lost a fumble in the exhibition opener. It's premature to write off Jenkins, but past due for him to make an impact this summer.

3. Rookie outside linebacker. Third-round choice Corey Lemonier looks like he could add something to the 49ers' rotation at the position. This game will provide another opportunity to check out Lemonier, who is making the conversion from defensive end to 3-4 outside linebacker. Aldon Smith made a similar transition as a rookie in 2011. Defensive coordinator Vic Fangio: "The difference between him and Aldon, at the same time, Aldon was in the lockout year and he didn't have all the spring work that Corey's gotten. So, from a know-how and technique standpoint as an outside 'backer, he might be a little bit ahead of Aldon at the same stage."