With the roster already short due to Lee's suspension, they simply can't afford to carry players who are "day-to-day" (unless they're at least able to pinch hit). You hate to put a player on the 15-day DL if they'll be unable to play for 2 or 3 days, but the Cubs may simply have no choice (especially if Ward and Floyd are both in that situation). If it's just one day they may be able to make do by bringing up a player just for tomorrow, delaying Dempster's return by one day, and living with an 11 man staff for a day, but beyond that I think they'd have to put at least one of them on the DL. Lee's dropping of the appeal and serving his suspension, which I thought made perfect sense at the time, now doesn't look so good in hindsight (especially since the reports that Lee would have missed 2 or 3 games anyway have since been refuted).