Cooper, 26, was a 12th-round pick of South Carolina in 2010. He was 4-2 with a 3.57 ERA working out of the bullpen in Double- and Triple-A this season.
Jackson, 26, was the 31st pick in the 2009 amateur draft and made his major league debut for the Cubs in 2012. He struggled making contact, striking out 59 times in 120 at-bats.
He hit .175 with four home runs that season but has been in the minors the past two years. He was hitting .201 with five home runs and 20 RBIs for Triple-A Iowa this season.