Ellsbury, 23, was drafted by the Sox in 2005. He participating in spring training this year and was called up to fill in for another player with an injury.
According to the Associated Press, Ellsbury received a standing ovation when he entered Fenway Park. "This has been a lifelong dream, to play in the major leagues," he said before taking the field.
Ellsbury is Navajo, one of the tribes that make up the Colorado River Indian Tribes.