Dunn battled shoulder issues and struggled to a 7.13 ERA and 1.30 WHIP in 17.2 innings with the Rockies before being designated for assignment and ultimately cut loose.

Dunn owns a poor 7.13 ERA in 17.2 innings on the season, inflated by the four runs he allowed in just one third of an inning in his most recent appearance Friday against the Padres. Infielder Pat Valaika was called up to take his place on the roster.

He missed almost two weeks with left AC joint inflammation. Phillip Diehl was optioned to Triple-A in a corresponding move.

It's unclear when Dunn suffered the injury, which is being described as shoulder inflammation, or how long it will keep him sidelined at this point. Prior to landing on the shelf, Dunn compiled a lackluster 5.19 ERA, 1.10 WHIP and 14:6 K:BB in 17.1 innings of relief (27 appearances). Thursday's starter, Peter Lambert, was summoned to the majors in a corresponding move.