The CBA is very specific as to who is eligible, what defines eligibility, what defines free agent, rookie free agent, restricted/unrestricted free agent and what defines an international player. There is no scenario that applies that allows DD to negotiate directly with team for a contract (without having entered/eligible for a WNBA draft). She did not enter into this year's draft and thus she is not able to contract.
The 2014-21CBA is available online for review. I've provided a reproduction of the eligibilty section for everyone's review.
The drafters of the CBA are quite clear on eligibility (copy/paste in a doc and enlarge):
ARTICLE XIII PLAYER ELIGIBILITY AND WNBA DRAFT
Section 1. Player Eligibility.
(a) Only players who are women are eligible to play in the WNBA.
(b) A player is eligible to be selected in the WNBA Draft if she: (i) will be at least twenty-two (22) years old during the calendar year in which such Draft is held and she either has no remaining intercollegiate eligibility or renounces her remaining intercollegiate eligibility by written notice to the WNBA at least ten (10) days prior to such Draft; (ii) has graduated from a four-year college or university prior to such Draft, or “is to graduate” from such college or university within the three (3)-month period following such Draft and she either has no remaining intercollegiate eligibility or renounces her remaining intercollegiate eligibility by written notice to the WNBA at least ten (10) days prior to such Draft or (iii) attended a four-year college or university, her original class in such college or university has already been graduated or “is to graduate” within the three (3)-month period following such Draft, and she either has no remaining intercollegiate eligibility or renounces her remaining intercollegiate eligibility by written notice to the WNBA at least ten (10) days prior to such Draft. For purposes of subsection (b)(ii) above, “is to graduate” shall mean that such player would graduate from the college or university she is currently enrolled in if she were to successfully complete the coursework she is enrolled in at the time of such Draft and such course load is commensurate with the previous course loads she has successfully completed. For purposes of subsection (b)(iii) above, “is to graduate” shall mean that the majority of the students in such class would graduate from such college or university upon successful completion of the coursework the members of such class are enrolled in at the time of such Draft.
(c) A player who: (i) is competing in a NCAA season (including any NCAA Tournament) during the period that begins ten (10) days prior to a Draft; (ii) has remaining intercollegiate eligibility beyond the season in which she is currently competing; and (iii) is otherwise eligible for selection in such Draft, may make herself eligible for such Draft by renouncing her remaining intercollegiate eligibility within the period beginning at the conclusion of her final NCAA game in the season in which she is currently competing and ending twenty-four hours thereafter (but in no event later than three (3) hours prior to the Draft).
(d) Notwithstanding Section 1(b) above, an international player is eligible to be selected in the WNBA Draft if she will be at least 20 years old during the calendar year in which such Draft is held.
(e) For purposes of this Section 1, an “international player” means any person born and residing outside the United States who participates in the game of basketball as an amateur or a professional. An international player who exercises intercollegiate basketball eligibility in the United States shall be subject to the eligibility rules set forth in Section 1(b)(iii) above.
(f) No player may sign a Contract or play in the WNBA unless she has been eligible for selection in at least one (1) WNBA Draft.
(g) No player shall be eligible for selection in more than two (2) WNBA
