...because coffee is for closers...
At the press conference announcing the Eric Gagne signing today, Jon Daniels said that Gagne would take over for Akinori Otsuka as the Ranger closer.
Why make the announcement now?
A few possible reasons...the most likely, in my mind, is that part of the deal with Gagne was that he wanted to go to a team where he would be the closer, and part of his signing with Texas was that they'd name him the closer. I'd be surprised if Boras didn't make it clear that Gagne wasn't going to sign with a team if he wasn't going to get to close, so Daniels making the announcement today would just be part of that quid pro quo.
You could also have a situation where Daniels is wanting to head off a "closer controversy" this spring, with speculation or discussions about who the closer is going to be, by making the announcement now.
Anyway, Gagne is (nominally, anyway) the new Ranger closer, and I imagine Otsuka is going to be on the block, whether the Rangers sign Barry Zito and/or Mark Mulder or not.