"Everything was feeling good, and then the calf grabbed me a little bit," Strasburg told reporters. "Luckily, the reports and stuff from the doctors [show] nothing major. It was just kind of more of a precautionary thing, take it day to day and see how it feels tomorrow."
He added: "Luckily, I feel like I'm a fast healer, so I don't think it would be something that could be a prolonged absence."
Nationals manager Dave Martinez noted the team was taking the cautious approach, given it's only spring training.
"There was really not much of a discussion," Martinez said. "Just wanted to pinpoint exactly what he was feeling. Other than that, he was coming out of the game. We're in spring training. There's no sense in pushing it."
Strasburg allowed just one hit while striking out four and issuing one walk in 2.1 innings before exiting.
The three-time All-Star had a tough 2020 campaign: He was 0-1 in two starts with a 10.80 ERA and 1.80 WHIP, and he had just two strikeouts in five innings. His season came to an end in August when he underwent surgery to address carpal tunnel syndrome in his pitching hand.
The 2019 season was a far better representation of the 32-year-old's hold on the league. He finished fifth in voting for the National League Cy Young Award after going 18-6 with a 3.32 ERA, 1.04 WHIP and 251 strikeouts in 209 innings.
In the postseason, Strasburg went 5-0 with a 1.98 ERA across six outings. He was named the World Series MVP after the Nationals defeated the Los Angeles Dodgers in seven games that year.
Max Scherzer and Patrick Corbin will continue to lead the rotation, but it will be up to Jon Lester, Austin Voth and Erick Fedde to fill out the back end should Strasburg be sidelined for the start of the regular season.