Seattle got the 29-year-old Hall from Milwaukee on Wednesday for minor league pitcher Ruben Flores. Hall wasn't in the lineup against the Tigers, but is expected to play in the upcoming series with Cleveland.
Seattle manager Don Wakamatsu said he hoped a change of scenery will help Hall, who hit 35 home runs in 2006 but was designated for assignment by the Brewers last week after hitting .201 in 76 games.
Olson was sent to Triple-A Tacoma. Wakamatsu said he wants the 25-year-old left-hander to make some mechanical changes in time for a return in September.