This happens a lot in preseason if you don't have enough depth and your starters are rested - the #1 and #2 CB will be benched at the time you have set in your misc gameplan options, which means you probably dropped to just having 2 CB's - who are probably not in shape enough to stay on the field. Remember, you can have 60 players active in the preseason.
I have a TODO item to have the AI consider the depth of each position so in your case you'd keep all 4 CB's active even after the starters have been pulled, but it's not yet implemented.
Last edited at 2/05/2015 1:53 pm