The 21-year-old right-hander is suffering from a muscle strain in his neck, and the club said the move was "for precautionary reasons." He is currently listed as day-to-day.
Strasburg, the No. 1 overall pick in the 2009 First-Year Player Draft, was scheduled to start for the East Division team in the Rising Stars Game of the Arizona Fall League. Right-hander and fellow Nats first-rounder Drew Storen was also selected for the club.
In four AFL starts, Strasburg is 3-1 with a 5.28 ERA. There is no word yet on when his next AFL start will come.
Angels prospect and Mesa Solar Sox right-hander Tommy Mendoza will start in Strasburg's place, and Nationals right-handed pitching prospect Josh Wilkie will take his place on the roster.
Alden Gonzalez is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.