Or, you could build a smaller run within the run just for Wed/Thurs.
It
should have its own door into the coop, to be opened only when you want them in the smaller run.
The smaller run should have poultry netting (chicken wire) around it to keep them from demolishing it all week, and it would also provide more protection from predators.
See rough sketch below: coop is at top, green area is Wed/Thur run, black line w/arrows is regular
fence.
Hope this is of help.
EDITED to resize img