I was just reading this online and didn't see it posted, i hope its not Thiago and its just bullshit...
Of significant potential interest, the Nevada State Athletic Commission has yet to release the drug screens from the night of Silva’s most recent fight, a UFC 125 win over Brandon Vera that took place Jan. 1 in Las Vegas.
Nevada State Athletic Commision executive director Keith Kizer confirmed with MMAjunkie.com that the commission is still investigating at least one sample from the event. While Kizer could not confirm whether or not one of those samples belonged to Silva, the NSAC executive did confirm that Silva was among the UFC 125 fighters who submitted a pre-fight screen
There were certainly rumblings about Silva during UFC 125 about the incredible mass that he seemed to have gained since the last time we saw him fight. It has also been reported that Rashad Evans is the possible replacement, but that so far has been denied by all parties. Now this is all just speculation at this point, more updates coming soon.