Suppose someone wants to go on a difficult military/research mission and he needs three people to accompany him. He looks at a list of possible candidates and marks two of them as [possible/presumable/likely what?]. {one word or idiom would be best}
I was thinking of the word "candidate" that I already used but neither Cambridge Dictionary nor Merriam-Webster has the definition that I need for this word.
I was thinking of the words "partner" and "companion" but you are not sure if they are going to accompany you or they are your final choice.
The thing is you mark them as likely to go and likely to be finally chosen by you but the choice is yours and theirs together. A person who remains to be determined by you and also yet remains unasked.
I tried to look for "potential companion" and "potential partner" as one word or idiom but all I found was "catch" - {informal} a person who is considered to be very suitable for a relationship but that is only related to a relationship.
I'm looking for a word like "catch" (noun) but in regard to a military/research mission and it shouldn't refer to a relationship.
Thanks to SteveES and Peter I've managed to find more words "preferences" and "potentials". However, I am unsure whether I can use them in such context.