Phillies Place Taijuan Walker on Injured List Due to Finger Inflammation

Spencer Turnbull returns to starting rotation; Michael Mercado called up from Triple-A for bullpen role.

Walker has struggled with injuries and performance, posting a 5.60 ERA in 10 starts this season.
The inflamed finger has particularly affected Walker's ability to throw his effective splitter.
Turnbull, who has a 2.63 ERA this season, will start Wednesday against his former team, the Tigers.
Mercado, a top prospect, is set to make his MLB debut after excelling in Triple-A with a 1.71 ERA.
Walker will continue to throw fastballs while on the IL to maintain arm strength.