49ers will use rotation on defensive line in 2013

Daily 49ers blog for NBC Bay Area website: To cut down on the wear and tear on Ray McDonald and Justin Smith and keep the defense fresher, the 49ers plan to rotate more players into the defensive line in 2013. http://www.nbcbayarea.com/news/sports/McDonald-Smith-Welcome-Depth-on-Defensive-Line-217939621.html