PHILADELPHIA -- Mets lefthander Steven Matz will have his next start pushed back a day to tomorrow night because of what he called stiffness in the right side of his back, the result of an uncomfortable night of sleep.

The Ward Melville product noticed the stiffness when he awoke Tuesday. He mentioned the issue to the training staff in what he called a "precautionary" measure.

"It's just kind of one of those things where you wake up and I slept wrong or something," Matz said.

DataPro sports draftees from Long Island

General manager Sandy Alderson said he does not expect the issue to impact Matz beyond the next few days. Logan Verrett will start in place of Matz tonight against the Phillies.

Alderson said the back issue has no relation to the lat injury that sidelined Matz earlier in the season.

"These are, I think, two different situations," Alderson said.

advertisement | advertise on newsday

Matz said his condition improved after receiving treatment. For now, the stiffness has not prompted the Mets to send the pitcher for more tests.

"It has definitely made an improvement," said Matz, who recalled dealing with a similar issue a few years ago.

Alderson indicated that Matz will be included on the Mets' postseason roster, though he left open whether the lefty would start or pitch out of the bullpen.

Mets videos

Said Alderson: "We expect Matz to be on the team."

With Jacob deGrom, Matt Harvey and Noah Syndergaard penciled into the rotation, the fourth spot remains up in the air. Matz and veteran Bartolo Colon are the considerations.

"Anything we decide now is tentative, anyway, based on what happens," Alderson said. "This is a good example of something can happen. So, we'll just have to see what develops over the next two or three days. But we don't expect this to have an impact on Matz beyond the next two or three days."