Youkilis had initially planned to appeal the suspension but decided instead to begin serving the suspension on Wednesday night.
Youkilis was cited by MLB vice president Bob Watson for "charging the mound, throwing his helmet at Porcello and inciting Tuesday night's hostilities," while Porcello was cited "for intentionally throwing pitches at Victor Martinez in the first inning and Youkilis in the second."
Tigers pitcher Edwin Jackson was fined for "aggressive actions" during the ensuing confrontation on the field.
Youkilis was originally in the lineup for Wednesday's game against the Tigers, batting fourth and playing first base. He will be replaced by Casey Kotchman. By sitting out on Wednesday, Youkilis will be eligible to return on Tue., Aug. 18 when the Red Sox play in Toronto. He'll miss the final two games of the series against Detroit and the three-game series over the weekend in Texas.
