Bradley's suspension will be served in Tuesday's game against the Rangers at Safeco Field. He had planned to appeal the suspension, which would have held it off until that process concluded, but he changed his mind.
"Originally, he was going to appeal it," Mariners manager Eric Wedge said. "He decided just to get it out of the way."
Joe Garagiola Jr., senior vice president of standards and on-field operations for Major League Baseball, made the announcement of Bradley's suspension on Tuesday.
Bradley was thrown out of Saturday's game by second-base umpire Gerry Davis in the third inning of the Mariners' 2-0 victory at Fenway Park, shortly after breaking an 0-for-22 slump with an RBI double that held up as the winning run.
Bradley was tossed for yelling at first-base umpire Todd Tichenor as he stood on second base after Miguel Olivo was called out at first on the next at-bat.
Wedge came out to argue the Olivo call with Tichenor and was returning to the dugout when Bradley was ejected.
"They said he made contact with the umpire," Wedge said. "I didn't see it. I was out there yelling myself. It's their call and their decision to be made."
Ryan Langerhans started in left and batted eighth on Tuesday with Bradley out.