Standing is a specific legal term that defines whether a party is allowed to sue, and injury is also a legal term in this case. Cornell Law School has a great intro on the legal requirements to establish standing using a 3-part test:
The plaintiff must have suffered an “injury in fact,” meaning that the injury is of a legally protected interest which is (a) concrete and particularized and (b) actual or imminent
There must be a causal connection between the injury and the conduct brought before the court
It must be likely, rather than speculative, that a favorable decision by the court will redress the injury.
In this case, seems to be the Supreme Court is skeptical that these doctors have satisfied this 3-part standing test, especially the injury in fact one. If SCOTUS decides that these doctors don’t have standing, then the lawsuit is dismissed.