Not sure the baggies are looking to replace Dorrans, as much as he just isn't in their first team plans.
Nicky Maynard is available on loan, not saying we'll get him but some clubs have started to make availabity known, for the opposite reason to the one you state.
Some clubs are on a tight budget, so they have to know what fees/ wages they have available before they can bring players in (e.g. if Tan is your owner and you are already over budget )