LaRoche aggravated the injury on Friday. The Nationals will be hopeful that LaRoche will be able to return once his 15-day stay is up.
With a roster spot available the Nationals have recalled Tyler Moore. Along with Moore, Kevin Frandsen is also an option at first base for the Nationals at this point.
In 32 games this season LaRoche had produced a strong .319/.421/.504 line with five home runs and 21 RBI.