Daisuke Matsuzaka is poised to start Wednesday at Wrigley Field against the Chicago Cubs, in the rotation spot formerly occupied by Montero. Matsuzaka likely will remain in the rotation until Dillon Gee returns from the disabled list, although assistant GM John Ricco was noncommittal beyond this next turn. Matsuzaka allowed two runs in six innings against the Arizona Diamondbacks in a spot start in the second game of a doubleheader Sunday.
Adam RubinRafael Montero is headed back to Triple-A Las Vegas.
"He's going to start on Wednesday. We'll kind of take it from there," Ricco said. "We haven't had a chance to really get together and discuss it. One of the great things about having Daisuke on the staff is he's got the ability to fill multiple roles for us. This is another example of that."
Gee's absence should be prolonged. Already on the disabled list with a strained right lat muscle, he had to stop throwing on flat ground because of discomfort after two tosses Sunday at Citi Field. Gee has not picked up a baseball since the flare-up. He currently is at the team's complex in Port St. Lucie, Fla.
"He's really still doing some lower-body stuff and seeing how the lat feels," Ricco said. "So he's a little bit away. He's not even throwing yet. So it's going to take time for him to get back and then ramp up again."
Montero, 23, was 0-2 with a 5.40 ERA and 1.60 WHIP in four starts. He had allowed five home runs. Terry Collins said Montero had curtailed use of his changeup, which is a plus pitch for the rookie.
Ricco portrayed demoting Montero as necessary because of Friday's extreme bullpen workload. He suggested it was not something being considered on its own merits because of Montero's performance at the major-league level.
The Mets had other options. They could have played down a bench player for a couple of days by demoting sparsely used Matt den Dekker. They then could have promoted another outfielder, perhaps Kirk Nieuwenhuis or Andrew Brown, once the bullpen had recovered from the overtaxing.
"It's really a move made out of necessity," Ricco said about Montero's demotion. "This wasn't something we had talked about. But when you play a long game like that and you're in the middle of a stretch with no off-days, sometimes you have to make adjustments. So we're going to option him out and bring in Carlyle to give us, at least in the short term, a little bit of length in the bullpen. ...
"Obviously [Montero] has some things he can work on. I know that was part of the message that Terry gave to him this morning. But this was honestly more about the circumstances. Generally, when you're doing something like this, one of the guys who just pitched a number of innings is the first guy you look at because you don't want to send out somebody who can pitch."
Montero should reenter Las Vegas' rotation, not work out of the Pacific Coast League team's bullpen, at least initially.
As a byproduct of returning to the minors, provided he remains there for at least a month, Montero should avoid Super 2 status after the 2016 season.
Carlyle, traveling from El Paso, Texas, was due to land in Philly at 2 p.m., about an hour before Saturday's first pitch. The Mets were not required to make a 40-man roster move because Carlyle only puts the organization at 39 (plus Matt Harvey and Bobby Parnell on the 60-day DL, where they do not count).
Carlyle last appeared in the majors in 2011 with the Yankees. He was 1-1 with one save and a 1.33 ERA in 20 1/3 innings with Las Vegas.