As Mark Zuckerman of MASN described, the starter immediately motioned to the bench that he couldn't continue after throwing an errant warm-up pitch.
Scherzer had completed just one scoreless inning on seven pitches before the spasms, although he also hit a three-run home run in the top of the second, his first of his career.
Although a finger injury limited him in the preseason, Scherzer remains one of the most reliable pitchers in the majors. Entering Tuesday, he had a 12-5 record and a 2.23 ERA in 21 starts. He also led the league with 145.1 innings pitched.
His consistency and ability to stay on the field are what have made him such a dangerous weapon for the Nationals.
The 33-year-old has made at least 30 starts every year since 2009, his first full season in the league. In his last four seasons, the right-hander tallied at least 210 innings pitched while earning an All-Star nod each year.
"I'm built for this," he said in February, per Chelsea Janes of the Washington Post. "I'm in my prime. I want the workload. I want all 33 starts."
Scherzer is also coming off the best year of his career, posting a 2.96 ERA while also leading the league in wins (20), strikeouts (284) and WHIP (0.968). This production helped him take home his second career Cy Young award, his first in the National League after winning the American League version with the Detroit Tigers in 2013.
It was the third time in four years he led his league in wins.
With Stephen Strasburg and Joe Ross already on the disabled list, however, another injury to a starting pitcher could be a tough blow for the Nationals.