The Chicago Cubs traded 2009 first-round draft pick Brett Jackson to the Arizona Diamondbacks for minor league relief pitcher Blake Cooper.
Jackson, a former top prospect of the Cubs, is in Triple-A. The outfielder made his major league debut in 2012 but has a .175 batting average with 59 strikeouts in 44 major league games.
Jackson, 26, is batting .210 with five home runs and 20 RBIs in 81 games with Iowa this year.
Cooper, also 26, has a 6.00 ERA in 24 innings over 17 appearances with Triple-A Reno.