J.D. Martinez holds an opt out after the 2019 season, but he also holds opt outs following the 2020 and 2021 seasons. His contract is front loaded, meaning he can earn $23.75MM in 2020, but that figure drops to $19.35MM in 2021 and 2022. It's not hard to imagine Martinez opting in for 2020 to avoid the suppressed free agent market while his contract is still in the front loaded portion.
So, if the Red Sox plan to cut salary, it may be their best player who is on his way out. They *should* offer Betts, a generational talent, a mega extension that surpasses the value of Bryce Harper's $330MM.
If the Red Sox truly want to cut payroll, it's tough to think they offer a mega contract to Betts. Additionally, Betts remains adamant that he wants to test free agency, stating, "Nothing is going to change."
So, the Red Sox have two choices from there. The first is play out the 2020 season with Betts, and risk losing him in the following offseason for a middling fourth round pick. The second choice is to trade him, and trading him in the winter would net more value than trading him next trade deadline.