ST. LOUIS — The Rockies are getting an infield keystone back.

Second baseman DJ LeMahieu was reinstated from the disabled list Thursday and was in the starting lineup for the afternoon game vs. the Cardinals. LeMahieu batted second, behind center fielder Charlie Blackmon.

LeMahieu missed 10 games with an oblique strain, an injury that sometimes can cause a player to miss significant playing time.

“I feel really good, and I can’t wait to get back,” LeMahieu said earlier this week. “I don’t handle sitting still very well.”

To make room for DJ LeMahieu, the club optioned rookie infielder Garrett Hampson to Triple-A Albuquerque.

LeMahieu, 30, was placed on the disabled list on July 21, his third stint on the disabled list this season. He’s batting .278 with, 22 doubles, eight home runs, 34 RBIs, 23 walks and five stolen bases in 72 games.

Hampson, 23, was called up July 21 and made his big-league debut at Arizona that night, starting at second base. He played in seven games (six starts), batting .300 (6-for-20) with one run, one double, one triple, two RBIs, four walks and one stolen base.

In other news, left-handed reliever Chris Rusin is scheduled to pitch in rehab games with Triple-A Albuquerque on Friday, Sunday and Tuesday. Rusin is on the DL with planter fasciitis. He threw live batting practice on Wednesday.

The Rockies are counting on Rusin to bolster their shaky bullpen.

“You hear me talk about first-pitch strikes and early-count outs — I want to see that happening in Triple-A,” manager Bud Black said of Rusin. “I want to see ball-strike ratios. I want to see the reports on his stuff, how’s the action to his slider, the action to his cutter, the quality of his changeup, fastball command — all the things we look for in a big league game.”