I love me some Yoho as much as the next guy, but I wonder if the injury history is what gives the Brewers pause.
Let's say they add him to the 40, and DFA a guy that has been decent (e.g. - Zastryzny, Jay), then Yoho gets injured right away... If that happens next April, no big whoop. But if that happens in September, then you lose two options for the Bullpen instead of just one.
Then again, if the Brewers think Yoho is so good that he's in the mix for setup-man innings, then I think they have to bring him up. OR, if they think he's a multi-inning guy, he should be planned on as a pseudo-piggy-back option with one of our lesser starters.
Yeah, you can disregard everything I've written, I think they should call Yoho up right away.