You would have to play a rookie over Mclean during his bye as well, so their byes are irrelevant.
I think Mclean is very likely to drop off with Wallis coming back (hopefully not, as he's in my team), but should still average around 90. Gray played midfield last week, and should average 100+ if he continues to play there, but probably more like 85-90 if he moves forward. I think the good outweighs the bad with Gray, so he'd be my pick.