The Rockies have acquired Clayton Mortensen from the Athletics for minor league righty Ethan Hollingsworth according to the team's Twitter feed. Troy Renck of The Denver Post says that Colorado has also designated right-hander Samuel Deduno for assignment (Twitter link).
Mortensen was designated for assignment last week to create room on the 40-man roster for Grant Balfour. The 2007 supplemental first round pick has appeared in eight big league games over the course of the past two campaigns. He has posted a 7.12 ERA with 20 strikeouts and 15 walks in 26 2/3 innings for the A's and Cardinals in his big league career. The 25-year-old has a 4.29 ERA with 6.9 K/9 and 3.3 BB/9 as a minor leaguer.
Hollingsworth was Colorado's fourth round pick in 2008. He owns a 4.33 ERA with impressive peripheral stats (8.4 K/9, 2.1 BB/9) in 376 minor league innings. Baseball America did not rank him as one of the team's top 30 prospects in the 2010 edition of their Prospect Handbook. Deduno, however, was ranked as the Rockies' 11th best prospect before last season. The 27-year-old has battled elbow issues in recent years, throwing just 47 innings (3.83 ERA) in 2010.