PHILADELPHIA -- New York Mets manager Terry Collins officially has pushed back rookie left-hander Steven Matz’s start a day, to Thursday’s series finale against the Philadelphia Phillies.

Matz experienced stiffness on his right side on Tuesday, which the Mets attributed to sleeping awkwardly.

Logan Verrett instead will start Wednesday at Citizens Bank Park.

Although the Mets have yet to declare Matz the fourth member of the postseason rotation with Jacob deGrom, Noah Syndergaard and Matt Harvey, team officials continue to make it easy to read between the lines.

General manager Sandy Alderson said pregame that Matz will be on the Division Series roster in some capacity. And then Collins reiterated after Tuesday’s 4-3 loss to the Phillies that Matz is not suited for relief because of his propensity for nagging ailments.

“He said he felt a lot better tonight,” Collins said. “I talked to him right before the game. Obviously we’ve got to play it safe. He said he got his treatment and really felt good, but there’s history there. That’s why I don’t like him out of the pen. He shows up and something’s stiff or something’s sore, then you can’t use him.”