Washington recalled outfielder Yadiel Hernandez from the alternate site in a corresponding move.
It's not clear when Soto suffered the injury. He told manager Dave Martinez just prior to Tuesday's game that he couldn't play, according to MASN's Mark Zuckerman. Soto then underwent an MRI.
After Tuesday's game, Martinez said that the IL stint is more of a precaution because it's early in the season and the team has several days off over the next 10 days, according to Zuckerman.
Losing Soto for even a brief period is is the latest blow to a Nationals team that's been riddled with injuries to start the season. The team already has five players on the injured list, including All-Star right-hander Stephen Strasburg and veteran lefty Jon Lester. Washington also had the start of its season delayed by a COVID-19 outbreak earlier this month.
Soto owns a .300/.410/.460 line with two homers and eight RBIs across 14 games for the Nationals in 2021. The 22-year-old was in a bit of a funk prior to going on the IL, having hit .167 over his last five games, and snapped an 0-for-11 slump - the second-longest of his career - with a double in Monday's loss to St. Louis.