Matz and the team believe he will miss only one start.
"We have the time right now just to miss one start," Matz said. "It's not the end of the world and (we can) just let it calm down and try to finish strong."
An MRI Thursday revealed no structural damage, but New York opted to be cautious with the oft-injured Matz. The DL stint will be his fifth since he made his major league debut in 2015.
"It's something that there's no reason to push him through at this point," manager Mickey Callaway said. "A different scenario we could, but it doesn't make much sense right now."
Matz will play catch before Saturday's game, one day before he was scheduled to start, and will be re-evaluated after that, Callaway said.
Matz didn't get out of the first inning of his most recent start. He allowed seven runs on eight hits in a 25-4 loss at Washington on Tuesday, the most lopsided defeat in Mets history.
Matz complained of tightness in his left forearm after the game. On Friday, he said he experienced some tightness during his start in Pittsburgh on July 26.
Matz is 5-9 with a 4.35 ERA in 21 starts this season. Since the All-Star break, he has a 12.34 ERA in three starts.
Corey Oswalt was promoted from Triple-A Las Vegas to replace Matz on the roster and in the rotation for at least this turn.
Oswalt is 1-2 with a 5.27 ERA in six appearances (five starts) for the Mets. He last pitched for the Mets on July 25 against the Padres.
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