The Cubs designated Blake DeWitt for assignment on Monday after claiming Adrian Cardenas off waivers from the Athletics. DeWitt, who the Cubs acquired in a trade with the Dodgers in July 2010, batted .265 with 11 doubles, five homers and 26 RBIs in 121 games last season. Cardenas, who was taken by the Phillies in the supplemental round (37th overall) of the 2006 draft and then acquired by the A's in a deal that sent Joe Blanton to Philly in July 2008.