New 49ers quarterbacks are a tough act

Meet C.J. Beathard, the 49ers' third-round pick from Iowa whom they traded up to select last week. Beathard hobbled through the season with torn abdominal muscles that required sports hernia surgery after he led the Iowa to a 12-2 record and berth in the Rose Bowl. The 49ers moved up to make Beathard the sixth quarterback selected, a surprise since many analysts had pegged him as a later-round pick. In a run-heavy, pro-style offense, Beathard completed 56.5 percent of his passes and averaged 148.4 passing yards a game as a senior. Beathard, who figures to learn behind starter Brian Hoyer and backup Matt Barkley as a rookie, credits his early exposure to the NFL for developing his determination to never leave the field. When he was with the Chargers, I saw guys like (safety) Rodney Harrison and (linebacker) Junior Seau. The Bears, Jets and Broncos called Mullens after the draft, but he chose the team that hosted him. Mullens was a three-year starter who also started the final six games as a 188-pound freshman. [...] Shanahan had said he wouldn't sign a fourth quarterback if the rookie didn't have a legitimate chance to stick in Santa Clara. Perhaps Shanahan spoke with Southern Miss...