A rooster is way easier to put back into a flock of hens than it is to add a single hen back into a flock of hens with a rooster.
It's wise to not handle a rooster while molting unless absolutely necessary. Separation is not punishment, it's a way to restore the bird back to health. A rooster that is struggling and left with hens is very likely to be brought down further than one that is given extra care and built back up. Once he's in prime condition, if the hen needs to be put in her place, he's the one that will do it if he's worth keeping.
Roosters have their own standing in a flock. Hens have theirs.
It would also be nice if the OP would post some more photos of the rooster and the spot she' concerned about now.
It's wise to not handle a rooster while molting unless absolutely necessary. Separation is not punishment, it's a way to restore the bird back to health. A rooster that is struggling and left with hens is very likely to be brought down further than one that is given extra care and built back up. Once he's in prime condition, if the hen needs to be put in her place, he's the one that will do it if he's worth keeping.
Roosters have their own standing in a flock. Hens have theirs.
It would also be nice if the OP would post some more photos of the rooster and the spot she' concerned about now.