March 7 (UPI) -- Colorado Rockies outfielder David Dahl will be sidelined for at least two weeks due to a stress reaction in his rib cage.
Dahl underwent further medical evaluation on Monday that revealed his injury. He had been sidelined while dealing with discomfort in his upper back.
The 22-year-old Dahl, expected to compete with Gerardo Parra for the starting left field job, will be re-evaluated in two weeks.
A first-round pick (10th overall) of the Rockies in 2012, Dahl debuted in the majors last season, batting .315 with seven home runs and 24 RBIs in 63 games for Colorado.
The 6-foot-2, 195-pound Dahl was hitless in four at-bats in two exhibition games this spring but has been sidelined since Feb. 26.