SAN FRANCISCO -- The Rockies placed rookie infielder Brendan Rodgers on the 10-day injured list with a right shoulder impingement, retroactive to Monday. That served as Tuesday's corresponding move for selecting the contract of right-hander Chi Chi Gonzalez, who started against the San Francisco Giants.

Rodgers, 22, started at shortstop in all three games of Colorado's series last weekend at Los Angeles. Rockies manager Bud Black said Rodgers felt discomfort in his shoulder after making one particular throw.

Subsequently, Black said, "the soreness started to intensify."

Rodgers, Colorado's No. 1 prospect per MLB Pipeline, was in his second stint of the season with the Rockies, having been recalled last Thursday. Since making his Major League debut May 17 at Philadelphia, he hit .224 with seven RBIs in 25 games. He also appeared in 37 games with Triple-A Albuquerque, batting .350 with 34 runs, nine homers and 21 RBIs.

The Rockies' 40-man roster is filled to its limit.

How to combat a slump

Black had a simple answer when asked how infielder Pat Valaika might consider curing himself of the batting slump that has nagged him for most of the season.

"You get out of it," Black said.

The skipper wasn't being insensitive. He was, however, restating the obvious: Ballplayers enduring an extended decline in performance must continue to work overtime and do all they can to escape the rut they're in.

Valaika entered Tuesday in a 0-for-30 skid that dropped his batting average to .050 (2-for-40).

"Like a lot of players who are struggling, I think there's a strong tendency to press, and I think there's tension in Pat's swing," Black said. "So I think Pat has to relax and get back to basics. His timing off; he's ahead on the breaking ball and behind on the fastball. Basically, the mechanics of his swing are fine. You don't get to the big leagues with a bad swing."