It remains to be seen who Palumbo will replace. With just a three man bench, it pretty much has to be a pitcher, and it would seem most likely that either Jeffrey Springs or Brett Martin would get optioned to open up a 25 man roster spot for Palumbo. That would allow the Rangers to option Palumbo after Wednesday night’s game, and then recall him, if necessary, on Saturday, June 29, which would be the next time the Rangers need a 5th starter (assuming Texas doesn’t find another stopgap option before then).
Sending down Palumbo would allow the Rangers to bring up Kyle Bird for Thursday’s game, allowing Bird to replace either Martin or Springs as the second lefty in the bullpen.
Alternatively, the Rangers could send down Peter Fairbanks, though he was just promoted recently, and it seems unlikely that the team would add him to the 25 and 40 man roster only to send him down less than two weeks later.
Another possibility would be for the Rangers to put Shelby Miller or Drew Smyly on the injured list, or else waive one of them. Both have been bad this year, and both have lost their spots in the rotation, though Miller has been a little better of late out of the bullpen. Each has an ERA above 8, though, and at this point in the season, Texas may feel there’s no point in continuing to keep each of them in the bullpen.