The Medic says in the promo that if they have to heli Missy out for X-rays, that she will leave the game. Implying that maybe the injury isn’t severe enough for her to be pulled, and they need the X-rays to make an informed decision.
FWIW, I think this something besides an ankle injury.
If it’s an ankle injury (per personal experience) they don’t really need the X-rays to determine whether they would need to pull her. If she can put weight on it, even with pain, she should be OK. If there’s a broken bone in her foot or ankle, or even if she’s just stretched the ligaments, such as in a severe ankle roll, she can’t use it and would be pulled, with or without X-rays. They’ll still take them, but they wouldn’t be the determining factor. If it’s a leg injury, the need to X-ray means that there is a possibility of a cracked leg bone. It might also be a knee injury, but they hurt like hell and the joint bends differently, and you pretty much know the story right away. It’s harder to tell whether a leg bone is cracked (and she would have to be pulled) or just badly bruised (and she could painfully continue), and you would need an X-ray to know.