Like DC’s Max Mercury, the Arrowverse’s Jay Garrick is a Golden Age speedster who has used his years of experience to influence and guide the younger generation of heroes. In addition to being a trusted friend to Barry, who often imparts some much-needed advice, he’s also regarded as an “uncle” to Bart in the future. Given his role, introducing Max Mercury runs the risk of bringing in a character who doesn’t add anything new to Team Flash or the show in general. Plus, Barry is already eight years into his superhero journey. He’s not really in need of a mentor anymore.
Given the similarities between Max Mercury and the Crimson Comet, it’s likely that The Flash will make significant changes to his character when it finally brings Max Mercury into the Arrowverse. That may be the only way it can avoid his story feeling like a repeat of Jay’s. To do that, it can focus heavily on the elements of his character that make him unique, such as Max’s constant jumping between time periods or his origin story, which saw him get his powers from a Native American ritual in the 1830s.
The Flash releases new episodes on Wednesdays on The CW.