PHILADELPHIA -- New York Mets rookie left-hander Steven Matz has been scratched from Thursday's start against the Philadelphia Phillies because of continued upper-back stiffness on his right side, jeopardizing his availability to serve in the Division Series rotation.
Matz originally was scheduled to start on Wednesday but had been pushed back a day because of the back discomfort.
Manager Terry Collins said Tim Stauffer or Sean Gilmartin will replace Matz in the series finale against the Phillies. The game has been moved from the evening to 12:05 p.m. ET at the direction of Major League Baseball to try to complete it ahead of expected rain.
"I just don't feel comfortable putting him out there," Collins said. "I know he'll go out there, but we don't need to subject him to having it get worse."
Matz had missed two months this summer with a strained lat muscle on the left side of his back before returning in early September.
"You're talking about a young guy who had a back problem that put him on the DL for a month," Collins said. "He comes out, throws three starts. And I realize it's not the same issue. It's on the other side of his back. But it's still an issue when you've got to get this guy ready."
Mets personnel believe Matz developed the stiffness from sleeping awkwardly. They expressed surprise it has persisted.
"It's still lingering a little bit, so we're just going to take it day by day," Matz said Wednesday afternoon. "We're not going to push anything. It's just a little stiffness in my back. When you wake up with a crick in your neck, it's kind of like that, just in my upper back."
After Wednesday night's 7-5 loss to the Phillies, Collins indicated that Matz was feeling better following treatment and medication for muscle spasms.
Collins said he hopes he can get Matz several innings in a game this weekend against the Washington Nationals. Regardless, Matz might 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.
Collins noted that if Matz were placed on the postseason roster for the opening round against the Los Angeles Dodgers and then ended up unable to pitch and were replaced, he also would be ineligible for the NLCS. The Mets want to avoid that scenario.
"I'm not very concerned," Matz said. "I know it's going to go away. It's just a matter of when."
Information from The Associated Press was used in this report.