The Cardinals had one of the worst bullpens in baseball last year, ranking 25th in MLB, according to FanGraphs. Even further, Brett Cecil and Chasen Shreve are the only left-handed relievers currently on the roster and they authored 6.89 and 3.93 ERAs last season, respectively.
Meanwhile, the Phillies had an impressively deep bullpen led by rookie right-hander Seranthony Dominguez. Like St. Louis, though, the Phillies lack elite left-hander depth with Adam Morgan and Luis Avilan as the lone southpaws in the 'pen.
The Mets had previously been tied to Miller earlier in the offseason and represent an interesting destination for the reliever due to his connection with current manager and former Cleveland Indians pitching coach Mickey Callaway.
The 33-year-old Miller is coming off of an injury-plagued season during which the southpaw posted a 4.24 ERA and 3.51 FIP over 34 innings with the Indians. 2018 was the final season of a four-year, $38-million contract that he originally signed with the New York Yankees.