It looks as though MLB is gonna play it safe and expand rosters for the first month or so of the season.
The MLB lockout this past offseason had a lot of strange effects on free agency, arbitration, spring training, and many other aspects of the game of baseball that we sometimes take for granted. One such side effect is that players, in particular pitchers, are having to get back in game shape on a significantly shortened timetable with roster restrictions (only 13 pitchers are allowed these days) that make it extremely difficult for players to ease back into playing significant innings safely.