Young, 25, is batting .266 with four home runs and 32 RBI over 84 games for the Twins this season.
Last season was a career-year for the Montgomery, Alabama native as he batted .298 with 21 home runs and 112 RBI over 153 games.
Since coming to the majors in 2006 with Tampa, Young has a .289 average with 63 home runs and 376 RBI over 689 games with the Rays and Twins.
Nelson pitched in 26 games with Detroit's Single-A affiliate at Lakeland this year and went 5-11 with a 4.87 earned run average.
The player to be named later will occur on or before October 15, 2011.