Per Evan Grant, Chris Ray has also made the Rangers' bullpen for Opening Day, and the last spot in the bullpen is down to Guillermo Moscoso, Willie Eyre, and Doug Mathis.
Mathis and Moscoso are on the 40 man roster, which would seem to give them an edge, but Luis Mendoza is going to be dropped from the 40 man roster any day now (and may be on waivers as we speak), so finding a 40 man roster spot for Eyre if he makes the club should be a non-issue.