NEW YORK -- The New York Mets placed rookie right-hander Christian Scott on the injured list with a right UCL sprain Tuesday, a major blow to a club battling for a National League Wild Card spot.

Mets manager Carlos Mendoza said Scott reported elbow discomfort to pitching coach Jeremy Hefner after he logged four innings Sunday against the Miami Marlins. He woke up with more soreness Monday and underwent an MRI at noon Tuesday. Mendoza said "multiple people" will examine the imaging before the club decides the next step for Scott. He did not rule out surgery as a possibility.

Scott, 25, made his major league debut May 4, holding the Tampa Bay Rays to one run over 6 innings. He was optioned to Triple-A Syracuse at the end of May, partly so the Mets could limit his usage after an elbow injury last year limited Scott to 19 starts in the minor leagues.

In all, Scott has logged 89 innings across 18 starts between the majors and Triple-A this season. He's recorded 47 of the innings in nine outings with the Mets and is 0-3 with a 4.56 ERA.

"It's always frustrating," Mendoza said. "But it's something he dealt with this last year. And that's why we were trying to protect him as much as possible. But it happened. So, again, I don't want to speculate here. Hopefully we get some good news, but we got to wait and see."

Scott's setback arose just as Kodai Senga was scheduled to make his season debut Friday against the Atlanta Braves as part of a six-man rotation. Mendoza said the Mets will continue with their plan for a six-man rotation in Scott's absence.

Jose Butto is a candidate to take Scott's rotation spot, but the right-hander hasn't started a game since June 28. He has instead given the Mets' beleaguered bullpen a boost by limiting opponents to one run in 10 innings in six relief appearances since being called up at the start of the month.

"Someone's going to have to step up," Mendoza said.

Senga, 31, was placed on the injured list to begin the season with a right shoulder strain. He suffered a series of setbacks to push his return later into the season than the Mets expected.

The Japanese right-hander, an All-Star as a rookie last season, gave up five runs on eight hits across three innings in Triple-A on Sunday in his fourth -- and likely final -- rehab start. He threw a bullpen session at Yankee Stadium on Tuesday.

"Very, very, very difficult both mentally and physically," Senga said through an interpreter. "But now that I'm ready to go, I want to put all that frustration towards the second half and perform."