ST. LOUIS -- The Cardinals officially optioned center fielder Harrison Bader to Triple-A Memphis on Tuesday, recalling outfielder Lane Thomas from Triple-A in a corresponding move.

The club also announced that it had claimed lefty reliever Adalberto Mejía from the Angels and that outfielder Marcell Ozuna (fractured right finger) would begin a rehab assignment with Memphis on Tuesday night. To make room for Mejía on their 40-man roster, the Cardinals transferred infielder Jedd Gyorko (right wrist/calf strain) to the 60-day injured list.

Bader, 25, has posted career lows in batting average -- his .195 is the lowest of Cardinals position players who made the Opening Day roster -- and slugging percentage (.339) this season. He hasn’t had a multihit game since July 3, and in his last 15 games, he’s 3-for-24 with nine strikeouts.

“The message was that he needs to play,” general manager Michael Girsch said. “He needs regular at-bats that he wasn’t getting up here. He knows that he’s out of whack and needs to get at-bats, but he’s a tremendous defensive player and a tremendous baserunner, and we fully expect him to be part of what we do going forward. He just needs to go out and get some at-bats.”

On Sunday against the Astros, his first start since July 21, Bader went 0-for-4 with two strikeouts without getting the ball out of the infield.

Despite the long slump, the Cardinals have relied on Bader’s defense and speed, usually double-switching him into a game in the late innings. But with a surplus of outfielders who are producing on the big league roster, the Cardinals can afford to let Bader take time in Memphis to find his swing.

“Clearly, he’s an elite defender,” manager Mike Shildt said. “He’s proven that, metrics prove it, eye test proves it. Great energy. Guy shows up to win, competes. Loves to play. Just a matter of him getting more consistent with his offense. The at-bats aren’t there for him right now, and he’ll go down and get some consistent ABs, get a few things better and be back.”

Thomas brings some of that defense in center, and he was batting .347 in July with the Redbirds, including a three-homer night Saturday that put him on MLB Pipeline’s Team of the Week.

Rehab roundup

• Matt Carpenter (right foot bone contusion) will stay on his rehab assignment with no definitive timetable, as the Cardinals third baseman continues to search for his swing. Since he was sent on rehab, he is 0-for-19 with seven strikeouts and four walks in six games.

Carpenter was sent to Memphis on July 23 and then Double-A Springfield on Friday. He will return to Memphis on Thursday for the Redbirds’ series against El Paso (Padres).

“He wants to get figured out before he comes up here, too,” Girsch said. “He’s at the point where if things click at some point, he can be up here quickly. But there’s no definitive timetable.”

Girsch said the Cardinals will revisit when Carpenter’s return might be “if he feels right and looks right and the results start to come.”

• Ozuna started for Memphis on Tuesday night to get three at-bats and play five innings. If that goes well, he’ll do the same thing Wednesday night. Girsch said Ozuna’s return will depend on how his hand feels and how he looks when he plays. When Ozuna was packing his bags for Memphis on Sunday, he was hopeful that he could return as soon as this weekend’s series in Oakland.

• Yadier Molina (right thumb tendon strain) had his thumb reimaged Monday and got a positive report from the doctors. Girsch said Molina was to start baseball activity Tuesday afternoon and would likely be swinging a bat by the end of the week.