While deemed quite worthy of a recent contract extension through 2015, OL Alex Boone is not considered a core player by any means. "But he's a definite keeper," one team insider said of the 6-8, 300-pounder origninally signed as an undrafted free agent in April 2009. "Worse case, he's a very solid swing tackle behind starters Joe Staley and Anthony Davis. Maybe if Davis falters and gets out of shape down the road, there could be an opening for Boone. He's a darned good player who totally redid his body, and he's got some nastiness to him. His biggest challenge is that he's not real quick." Boone more than held his own in Week 14 when he replaced the injured Staley in an ugly loss in Arizona. "He competed. I thought he did a good job," head coach Jim Harbaugh said. "I definitely don't think there's anybody thinking it was a dazzling performance on the offensive side of the ball. But, he did a very good job."