Is contestant a simple subject

The noun 'contestant' can be a simple subject or any other function of a noun; for example:

Subject of the sentence: The contestant won a prize. (simple subject)

Subject of a noun clause: The prize for the contestant who won is a thousand dollar gift certificate.

Object of the verb: We met the contestant who won the prize.

Object of the preposition: They presented a check to the winning contestant. (object of the preposition 'to')