Well that would be on him for opting out. What do you see a 32yo DH getting as a free agent and from who?
The higher spenders in the AL all have DH's under control for next season, and while JD would be an upgrade for Houston over, say, Gurriel, they also recently took on Greinke's salary and might not have the budget. The rebuilding teams are not going to build around a DH, except maybe the White Sox. Although all indications are they plan to re-sign Abreu.
And that leaves the NL, where the DH is coming, possibly in 2022.
The market was not as kind to Martinez a hoped for last time., and now he is 2 years older. I doubt he opts out until after 2020 when his salary drops. He stands less to lose...