From the same softball tournament I posted to earlier - at the last game I really struggled with the sun behind the players, but I wanted to give some backlit shots a try. Took a little time to figure out how I wanted to process them, but here's what I came up with. See what you think.
#1
Canon EOS R5RF70-200mm F2.8 L IS USM lens153mmf/2.81/3200s100 ISO+0.3 EV
#2 - infielders give congrats to the pitcher for striking out the batter
Canon EOS R5RF70-200mm F2.8 L IS USM lens200mmf/2.81/2500s125 ISO0.0 EV
Yes, on the pitcher shot there is something funky with the front of the uniform. Honestly, I didn't look hard enough at the original to see what was going on. I remembered there was a bit of white on the side of the uniform, but looking at it again I see that the white is down at the bottom of the uniform side and doesn't go the whole length.
Went back to the history in LRC and figured out that the auto selection of the subject did not pick up all of the black on the front of her uniform shirt. Did a quick redo (below) and had use the brush to add that front, black part of the shirt to the mask. Looks better, but could still use some tweaking.
Lots of dust in the air that day!
#1 sooc
Canon EOS R5153mmf/2.81/3200s100 ISO+0.3 EV
Here is the history on the first time I processed things.
Here is the quick redo with the subject mask fixed a little better.
I think you are spot on: the deficiency is simply masking technique. I see some areas in both photos where the masking layer simply doesn't match the subjects.
Another thing I now notice is the foreground and background don't don't quite match now. I think the bg just needs a bit more contrast. I don't know if you shoot RAW or not, so you may not have a lot of wiggle room if you shoot JPEG.
I do shoot RAW, although the quick edit I did was from a jpg. Played with that same jpg today and added more contrast with the background, but that just exacerbated the edges of the mask on the player - made it so you could see the imperfections of her mask, especially around her feet. So, I went back to the mask on her and increased exposure and did a little dehazing. It's still not great since the original exposure was not the best, but I almost like the more highly exposed background more than this one.