MILWAUKEE — Tommy Hunter’s second two-inning relief appearance of the season issued him a ticket to the Mets’ injured list Tuesday.

The veteran reliever indicated he is bothered by back spasms.

A day earlier Hunter allowed five earned runs over two innings after Carlos Carrasco departed in the fifth.

Denyi Reyes was selected from Triple-A Syracuse to replace Hunter and give the Mets a fresh arm capable of pitching multiple innings.

The Mets placed Bryce Montes de Oca on the 60-day injured list to create space on the 40-man roster for Reyes. Last week Montes de Oca underwent Tommy John surgery.

The right-hander Reyes appeared in three games for the Orioles last season and was with the Mets this year in spring training.

Reyes, who needed three pitches to get the final two outs in the sixth inning on Tuesday, has minor league options remaining that will allow the Mets to shuttle him between Syracuse and the major leagues without needing him to clear waivers.

“I thought we had a really good offseason with guys [minor league free agents] that we wanted to bring in, and [Reyes] was one of those guys,” manager Buck Showalter said before the Mets’ ugly 9-0 loss to the Brewers. “I knew we were going to have a challenge these first eight days getting to the off day with the pitching. I was trying to get as deep as we could with [Carrasco], but we couldn’t.”

Hunter, by his own count, has undergone at least seven back surgeries over the course of his career, so the spasms are hardly surprising to him.

“It comes and goes and it happened a few times last year,” Hunter said. “It sucks, but we’ll be back. It just takes a few days and usually they go away and you can’t be out a guy for a couple of days.”

The rules governing the usage of position players to pitch had Showalter rooting against Mark Canha hitting a three-run homer on Monday that would have cut into the Brewers’ 10-0 lead.

Showalter’s plan (which he executed) was to insert Luis Guillorme as the pitcher for the eighth inning, but that wouldn’t have been allowed unless the Mets trailed by at least eight runs.

It’s because of that rule Showalter briefly had Adam Ottavino warming up in the bullpen.