I'm no expert, but I'll tell you what I think. There are some guys who you shouldn't worry about too much (Soriano, Reyes, Vlad, Turnbow). Barring injury, you know what you're getting with these guys.
You also have a few guys that have a nasty history of injuries (Chipper, Thomas, Sheets) to keep an eye on. If healthy, they're good plays, though.
I would be a little leery that you have a good amount of question marks and unestablished guys on the team, like McCann, Morneau, Swisher, Bonds, Preston, Holliday, Guillen, Edwin, Blanton, Duke, Gonzalez, Verlander, Baker. Chances are, they won't all dud, but they probably won't all turn out great, either.
My advice would be to just watch their progression. Any team can be salvaged this early in the season. Don't worry too much, but keep a sharp eye on the waver wire and trade landscapes. Again, I'm not a pro, but I have overcome early season slumps to go from worst to first simply by being realistic. If you honestly think a player is bombing, and have legitimate reasons to think they are done, don't be afraid to trade or even drop them. Otherwise, be patient. Baseball stats are very consistent from year to year. Good luck!