Chambers, 25, was batting .308 in 37 games for Memphis this season with one home run and 12 RBI. He was batting .327 (17-for-52) in May and has hit at a .331 (31-94) clip against right-handed pitching this season. The left-handed hitting Chambers appeared in 18 games for the Cardinals last September, collecting three hits in eight at-bats (.375) with 4 RBI.
Dickson, 27, was 2-3, 3.42 ERA in eight starts for Memphis this season. He has allowed 51 hits in 47.1 innings pitched, walking just 11 while striking out 31. The right-handed throwing Dickson held right-handed batters to a .227 BA. He fanned a career-high 10 batters in an 8.0 inning effort against Iowa on May 2.
Dickson made four appearances for the Cardinals last season, including his first Major League start on Sept. 1 at Milwaukee.
Chambers will wear uniform # 56 and Dickson #65.