The phrase "became seasoned" refers to the process of becoming experienced, often through repeated exposure to a particular activity or situation. Antonyms for this phrase might include "unseasoned," "inexperienced," "novice," or "green." These terms describe someone who is new to a particular field, situation, or activity and lacks the knowledge or skills of someone who is seasoned. Other possible antonyms for "became seasoned" might include phrases like "lost expertise," "regressed," or "fell behind," which suggest a decline in skills or knowledge that someone previously possessed. Ultimately, the antonyms for "became seasoned" are words that describe the opposite of experience, expertise, or familiarity.