The names in contention for defense secretary under Trump can change frequently and may not always be known to the public. However, as of the last update, these were the key contenders:
1. James Mattis: A retired Marine Corps general who served as the 26th United States secretary of defense from January 2017 to December 2018.
2. Mark Esper: He served as Secretary of the Army from 2017 to 2019 and Defense Secretary from 2019 to 2020
