The New York Mets don't know how they'll be able to use Steven Matz in the NLDS after he was scratched from Thursday's start against the Philadelphia Phillies because of continued upper-back stiffness on his right side.

Matz originally was scheduled to start on Wednesday, but had been pushed back a day because of the back discomfort.

"I just don't feel comfortable putting him out there," Terry Collins said. "I know he'll go out there, but we don't need to subject him to having it get worse."

The left-hander may now end up getting left off the Division Series roster, with Bartolo Colon instead joining a rotation with Jacob deGrom, Noah Syndergaard and Matt Harvey.