They could effectively accomplish the same thing by signing some replacement player that is still a free agent or just calling up some more of their triple A filler. Montgomery might be marginally better than one of those guys, but who the hell cares when you're 30 games under .500?
One of the beauties of being a terrible baseball team is that you aren't forced to do anything. You don't have to rush your prospects if you don't want to. You can just call up the next warm body and continue being terrible because, what's the difference?
Just go sign Boone Logan or AJ Ramos or Joaquin Benoit for the league minimum and get a future asset whenever you're gonna make a trade, however marginal he is.