The Texas Rangers have optioned the following players currently on the 40 man roster to the minor leagues:
Miguel de los Santos
These guys getting sent down wouldn't be classified as at all surprising, as none of the seven were seen as having legitimate shots at the Opening Day roster. While there was some lip service given to Perez having a chance at winning a bullpen job, the reality is that, barring some sort of exceptional confluence of events, Perez was going to go to AAA to work on being a starting pitcher.
What is noteworthy is that Robbie Ross is among those still in camp, with Jon Daniels saying today that he has a legit shot at being the Rangers' bullpen lefty. Ross is not on the 40 man roster, but he's older than Perez, and he's seen as more likely than Perez to eventually end up in the bullpen anyway. I'd be shocked if Ross actually makes the Opening Day roster, but I do think the Rangers want more looks against Ross against higher-level competition, in order to better evaluate how close to being ready he is, and how realistic an option he may be out of the bullpen later this season.