In late August 1908, Bush, then known as "Ownie", was sold by the Indianapolis club to the Detroit Tigers. He joined the Tigers in mid-September after Detroit's starting shortstop, Charley O'Leary, had been injured. Bush replaced O'Leary at shortstop for the team's final 20 regular season games. Bush's performance in the final weeks of the season, during a tight pennant race, was credited with having "thrust the panting Tigers first over the line." Because Bush had not been with the Tigers for more than 30 days, he was ineligible to play in the 1908 World Series. At the end of the 1908 season, "Baseball Magazine" wrote: