NFL rosters are mostly set until training camp, making this a good time to revisit a subject we hit pretty hard after the draft: how much raw playing time from last season each NFC West team will have to replace in 2013.
A few highlights and notes:
Most turnover: The Arizona Cardinals return 28.9 percent of their 2012 snaps at quarterback, the lowest percentage for any team at any position group. The St. Louis Rams are at 29.6 percent returning at running back. The Cardinals' secondary is at 30.8 percent returning, followed by the Cardinals' running backs at 36.9 percent. Those are the only four positions with less than 40 percent of 2012 snaps remaining on the roster. Arizona has the lowest percentage returning overall (60.9 percent).
Least turnover: The Rams have 100 percent of their quarterback snaps from 2012 still on the roster. The 49ers' running backs (99.4 percent) were next. Nine of the teams' position groups return at least 90 percent.
Injury factor: The percentages would be lower at some positions if we removed from consideration players who might not be available because of injuries. Those players include receiver Michael Crabtree, running back Kendall Hunter, receiver Kyle Williams and receiver Mario Manningham of the 49ers and defensive ends Chris Clemons and Greg Scruggs of the Seahawks. Tight end Anthony McCoy remains with Seattle, but he is on injured reserve, so I did not count his snaps as returning.
Suspension factor: Several NFC West players are facings suspensions to open the 2013 season. I did not remove their 2012 snap totals from consideration because all of the players are expected to factor for their teams this season.