DL Question

So yesterday, to the surprise of absolutely no one, Chien-Ming Wang was placed on the disabled list. But what might surprise some people (and certainly surprised me) is the supposed cause: "weakness in the adductor muscles in both hips."

So which is crazy: (a) that alleged injury, (b) me, or (c) emphatically both? First of all, "weakness" isn't really an injury by itself, is it? And also...what the what? There has been no indication that Wang's hips were bothering him. We've been hearing for a week that he was DL-bound, but it was his foot, or a tired arm, or something -- never the hips.

So my question is: what's to stop a team (aside from the team doctors' Hippocratic Oath, I suppose) from making up an injury to free up a roster spot? If you've got a guy who is struggling or who you just don't need right now, but you can't send him down without risking losing him to the waiver wire, is there any reason you can't just say "he's got...uh...Transient Developmental Aversion Disorder With Itching! Yeah, that's the ticket!" and put him on the DL?

From my persual of the Official Rules and everything else I can find, there's nothing to suggest that a team can't do this. And with the gentlemen's club of GMs and such being what it is, it's hard for me to imagine one GM calling another's bluff and having a supposedly "injured" guy tested or something anyway.

So: (1) what do you think the odds are that the problem is really in Wang's hips, and not in his head or, well, his innate baseball talent? And (2) why don't teams do this all the time--essentially send a guy down who can't be sent down, under the guise of some dubious injury? Or (3) do they do it all the time, and we're just too naive to notice?

I know, this is all very conspiratorial of me. It seems very, very likely that something very real is wrong with Wang, and it may well be his hips. But I'm serious about the question--is there anything to stop a team from doing this, and if not, why don't they?