The All-Star will wear a splint to protect his left thumb during the best-of-five series between the longtime rivals. He suffered strained ligaments while making a tag during a Sept. 20 game against the Cubs.
Joining Molina on the Cardinals' roster announced Thursday were four rookies -- outfielder Randal Grichuk, outfielder-first baseman Stephen Piscotty, outfielder Tommy Pham and infielder Greg Garcia.
The Cardinals left first baseman Matt Adams, infielder Pete Kozmaby and relievers Randy Choate and Steve Cishek off their NLDS roster. Adams struggled after returning late in the season from a torn quadriceps.