I'm assuming the CF issue depends on a large part on when they think Harper is coming up. if Harper is up in June-July, then they have a crowded OF (Harper RF, Morse LF, and some other OF that played CF for the first few months).
IMHO they need to get Morse back to 1st, which would give them the option of harper in LF, Werth in RF, and lead-off batter in CF. That means trading LaRoche before the trade deadline and landing a top-notch CF in the off-season.
If they are thinking more like Morse-Werth-Harper, or Harper not being ready next season, then maybe they go for a short-term lead-off/CF option like Juan Pierre or DeJesus.