The Miami Herald's Clark Spencer reported Volquez is also dealing with a knee injury that would've been season-ending on its own.
The right-hander appeared in 17 games this year, going 4-8 with a 4.19 ERA and a 4.34 FIP, per Baseball Reference.
Volquez is still under contract with the Marlins for the 2018 season, with $13 million due to him next year. Undergoing Tommy John surgery will almost certainly mean he's unable to pitch at all in the final season of his contract.
Volquez turned 34 in July, so it's not a stretch to say his elbow injury could potentially be career-threatening if he's unable to pitch in 2018. Few teams will likely be willing to take a chance on a 35-year-old pitcher coming off Tommy John prior to the start of the 2019 season.