MIAMI -- Rafael Montero's return to the major leagues lasted only one day.
The Mets summoned left-handed reliever Jack Leatherisch from Las Vegas to take Montero's spot.
Team officials opted to stay with an extra pitcher and four-man bench until David Wright returns from the disabled list as soon as this weekend.
The Mets wanted to promote someone already on the 40-man roster, which left Leathersich as the only eligible pitcher at the Triple-A level.
Leathersich, 24, has been a strikeout machine in the minors. A fifth-round pick in 2011 out of UMass-Lowell, he has fanned 347 of 893 professional batters he has faced -- a whopping rate of 15.3 batters per nine innings.
However, the 5-foot-11 Leathersich is not a flamethrower. His fastball sits in the low-90s. And because of control issues in past seasons with Las Vegas, he would fall behind batters, who then would not chase his fastball up in the zone. Leathersich walked 36 batters in 37 1/3 innings with Las Vegas in 2013 and '14.
Leathersich had similar control issues during spring training last month. He walked five and hit a batter in 4 2/3 Grapefruit League innings.
However, Leathersich displayed better control to open this regular season with the Pacific Coast League club, according to catcher Kevin Plawecki. In seven relief appearances, Leathersich had a 2.57 ERA and had allowed four hits and two walks while striking out 13 in seven innings.
"He was throwing a lot of strikes," Plawecki said. "And I know that's something he's been trying to work on for a while. He commanded the zone really well when I was there. Hopefully he'll continue to do it."
Montero's U-turn to Vegas was expected. Since he logged 85 pitches, he would not be available for multiple days while recuperating. And the Mets had no interest in playing with a 24-man roster in the interim.
Montero will return to Las Vegas' rotation. The Mets already have identified at least one other date in which they plan to use a spot starter, and Montero's name should be front and center among the candidates for that game.
"That's the decision that was made. I can't control that," Montero said about the demotion through an interpreter late Tuesday. "I'm just going to go down and pitch and work on my things and be ready when another opportunity comes."
Montero was charged with three runs on five hits in 5 2/3 innings. The final run scored when Buddy Carlyle inherited a runner on third base from Montero and tossed a wild pitch.
"Very impressive. Very good location," manager Terry Collins said about Montero. "Early in the game he had a little too many 3-2 counts, but he made the pitches when he had to make them. I thought he threw the ball very, very well tonight."