Matz's latest turn in the rotation was skipped after he felt soreness in his left forearm following his previous outing.
"It was enough concern for me to say something to the trainers," Matz had said. "It was just sore, so I said something."
The Mets wanted to err on the side of caution with the 24-year-old, a key piece of their dynamic young rotation who has already had Tommy John surgery in 2010.
David Adler is a reporter for MLB.com based in New York. Follow him on Twitter at @_dadler. This story was not subject to the approval of Major League Baseball or its clubs.