Fullbacks are usually the most exposed and often criticised players on the pitch. You don't get through a season with some errors that look like big gaffs. All our fullbacks have had them lately, or at least the ones who play anyway. White is a victim of that as much as anything. Plus with the way we play there isn't the chance for redemption the way more attacking full backs can gain some extra good will after errors.
Think Rickys point about minutes played is a good one too. We've quite a few in that boat at the moment. Odegaard springs to mind straight away.