The description is a little unclear:
- I presume that the 4th user shown in the illustration is supposed to be labeled User 4 (current member)?
- the 4th user listed also appears disabled (grey), the reason for which you do not explain.
- a lot of context is not known.
Nevertheless, making assumptions, then, that
- user listed 4th is supposed to be labeled User#4,
- and disabled because that user is already registered, then....
A more user-friendly solution would be to
- Remove from the list entirely the users that are being processed (awaiting, current) and not selectable, and put them into a separate status list. This will leave the selectable list composed of only the options that are selectable, which will require less cognitive work from the person using the interface because it is "clumped" into groups that are meaningful to the primary concept action of the screen ("register a user").
In large scale cases (many users), the groups could be collapsed by default, along with some summary scent. Not necessary for only 1.
Groups would also allow you to more clearly add additional contextual actions, if that is a future plan. E.G. "Cancel Registration".
- The label "current member" is ambiguous in this context. Try revising it to "Already registered" or some similar not-ambiguous label that also connects to the form title/action.
The resulting display would structure like this:
Select User To Register:
() User 2
() User 3
Awaiting Confirmation (1):