It seems to me that Vernon Wells and Alex Rios are playing too shallow. I know Vernon likes to play shallow as he thinks he can get back on well-hit balls, but there seem to be a lot of balls getting over both his and Rios' heads. I'd rather see them play a few steps further back if it would prevent a few doubles, particularly with runners on. On balls hit in front of them, base runners would have to respect their speed and hold up and if the ball dropped in with the arms on these guys, we probably hold them to a single base anyway.
The defensive positioning is not just up to the fielders. I recall hearing Jerry and Alan talking about the coaches having a responsibility in this regard, particularly Gene Tenace, if I remember correctly.