On Scott Tolzien's addition to 49ers' roster

The San Francisco 49ers ideally would have added an experienced veteran backup quarterback as insurance for Alex Smith and Colin Kaepernick.

Of course, the 49ers of the past decade have known better than most the difficulties associated with finding quality at the position.

That explains why the 49ers claimed Scott Tolzien off waivers from the San Diego Chargers. They didn't like any of the available veterans enough to clear a roster spot for one.

Tolzien, an undrafted rookie from Wisconsin, had impressed Chargers starter Philip Rivers with how quickly he grasped the playbook in camp with San Diego. He is what teams generally prefer in their third-string quarterbacks: a quick study willing to put in the work. There simply aren't enough reps or coaching resources for teams to coddle third-stringers, particularly once the season starts.

Tolzien, a bit undersized at 6-foot-2 and 212 pounds out of college, lacks the strong arm and overall physical skills that separate quarterbacks on draft day. But he finished his college career with a 21-5 starting record and was the Johnny Unitas Golden Arm winner last season.

There are no guarantees for Tolzien or anyone else around the fringes of NFL teams' rosters. No matter how much the 49ers might want to develop him, they've already identified Kaepernick as their preferred long-term starter. Injuries or opportunities to land more talented players could lead the team in another direction down the line.