I guess I just don't see what the concerns center around. Has that been reported? Was there an injury that was kept from the sportswriters? Is it something about the knee problems from a couple years ago? Because just generically, just based on the numbers and the news reports I've read, it makes no sense to be overwhelmingly concerned about Bay's health -- no more than for any player you're giving a multi year megabucks deal to anyhow.
As for taking a physical, that tends to be a formality, as well you know. Without knowing too many specifics, I wouldn't get too hyped up about the fact that the physical associated with a deal that only came public yesterday is yet to be completed.
I suppose you have a point, but calling one of the top 5 HR hitters in the American League last year, and a consistent .900OPS guy, a "middling" player, should entitle you to a bit of ridicule IMHO. It's one of the ways forumites convince each other to get properly informed after all.