WASHINGTON -- Steven Matz's bid to complete the first full, healthy season of his career is in jeopardy. The Mets pitcher complained of left forearm tightness after Tuesday's 25-4 loss to the Nationals, according to Mickey Callaway, and planned to travel to New York on Wednesday for an MRI on his arm.
Forearm issues can often dissipate with rest, but they can also hint at more serious elbow problems.
"I think we need to get him checked out just to make sure that's not the case," Callaway said.
Since posting a 2.91 ERA over a 13-start run from May 5-July 12, Matz has struggled, producing a 12.34 mark over his last three outings. That includes Tuesday's start, in which Matz allowed seven runs on eight hits, recording merely two outs.

Afterward, Matz said he believes he "is going through a dead-arm phase" not unlike those most pitchers experience over the course of a season.
"I feel healthy and good," said Matz, who was unavailable to comment further on Wednesday. "It's hard to describe."
The forearm discomfort is more alarming for Matz than for most pitchers, however, given his injury history. A recipient of Tommy John surgery in 2010, Matz also underwent operations to remove bone spurs from his left elbow in 2016 and to reposition the ulnar ligament in his forearm the following year. Since reaching the Majors in '15, Matz has also spent time on the disabled list due to a torn left lat muscle, a left shoulder impingement and left elbow inflammation.
Overall, Matz has made 56 starts over the past three seasons, going 16-24 with a 4.31 ERA. He is one start shy of his career high of 22, set in 2016, and 24 2/3 innings off his career best set the same season. Along with Zack Wheeler and Jacob deGrom, Matz is one of three Mets starters on pace to set career highs in innings.
"We have to make sure that we understand that," Callaway said, "and take every precaution necessary to keep them on the field as much as possible."
The Mets expect to know more about Matz's condition by Thursday.
Back to normal
Less than 24 hours after departing Tuesday's game in the first inning due to dizziness and dehydration, first baseman Wilmer Flores was back in the Mets' lineup at first base. Flores received no treatment beyond a regular intake of fluids.
"I think everybody's a little perplexed," Callaway said of the issue, which went away within hours of Flores leaving the game.

Roster move
To make room on the active roster for Noah Syndergaard, who came off the DL to start Wednesday against the Nationals, the Mets optioned reliever Tim Peterson to Triple-A Las Vegas. Peterson owns a 6.53 ERA in 18 appearances this season.