I suppose it's too small an area to mole plough, which would help drainage with minimum soil disruption. Ideally you would want to increase the
earthworm population of the poached ground, but they don't like acid, wet soil. You would need to look up how to promote earthworms in your soil and rainfall type, which might include liming - easy to do by hand over such a small area. You will be looking at a long term approach, seeing gradual results over 2 or 3 years, as Sally says, not an instant fix.
Oh no, I'm off to look up earthworm repopulation, can't resist
I'm back:
https://core.ac.uk/download/pdf/40101965.pdfThis is a PDF of a PHD study into earthworms, from Stirling Uni. On my rural broadband which functions at the speed of glaciers, it took a while to download, and I have only had time to skim through, but have pinned it for later study. It seems to give info on just about everything you could need in an investigation into the understanding of earthworms.
From a general search, it seems that soil disturbance eg ploughing, will have a detrimental effect on the worms, and the supply of food for them (dead vegetation and leaves) will help their numbers.
So that might imply that it would be best to leave that patch ungrazed for this year to give the soil a while to start a natural recovery, perhaps spreading manure and compost on the surface.