The team announced Thursday that it has placed Seager on the IL, activating infielder Matt Beaty from the injured list to replace him.
The injury to Seager occurred Tuesday when he was attempting to score from second base in a game against the Los Angeles Angels in Anaheim.
First reports were that Seager had a Grade 2 strain, which usually needs four to six weeks of recovery.
On Wednesday, the team said that an MRI revealed a strain "between Grade 1 and Grade 2." No timetable for Seager's return has been set.
In 66 games this season, Seager is hitting .278 with eight homers and 38 runs batted in. Last season, Seager appeared in just 26 games for the Dodgers because of injuries.
Beaty returns to the team after suffering a hip injury. In 17 games this season, he is hitting .286 with seven runs batted in.