ST. LOUIS -- Indians manager Manny Acta said catcher Carlos Santana is still in the process of getting his rhythm back since returning from the 7-day disabled list due to a concussion he sustained on a foul ball taken of his mask on May 25.

Santana is 2-for-20 in five games since his return. Santana was hitless in three games before his concussion, and has seen his average drop from .262 to .229. Acta said the week-long layoff was a factor in Santana's struggles early in his return.

"But that doesn't mean it's the reason why he's where he's at," Acta said Saturday. "To him, it's going to continue to be a battle, a battle he continues work with his body movement at the plate."

Santana will play first base on Sunday against the Cardinals, and Lou Marson will relieve him behind the plate.

The switch-hitting Santana hasn't had much more success at either side of the plate this season. He's batting .217 against lefties and .235 against right-handers this season. Acta said the repercussions of Santana's concussion seem to have affected the catcher batting right and left.

The manager sites the leg kick in Santana's swing as a reason for his slow progress.

"It's a high leg kick just like every hitter that does those things, it's a lot of rhythm," Acta said. "Guys that rely on that have a tendency to be up and down at times because that's what pitchers try to do. Less is more. The less body movement you have at the plate, the better chance you have to keep those eyes quiet."

Choo stays aggressive in leadoff spot

ST. LOUIS -- Since moving to the leadoff spot on May 14, Indians left fielder Shin-Soo Choo is batting .303 (30-for-99) in 24 starts. Choo is still hitless (0-for-9) entering the third and final game of this weekend series in St. Louis. But he won't be looking to do anything differently on Sunday, he'll just try to continue being aggressive at the plate and looking for solid contact.

Choo grounded out three times on Saturday, and hit a scorching liner to Cardinals third baseman David Freese in his final at-bat. Choo hit the ball hard in each at-bat, but just couldn't find the holes.

"Last two days I haven't been on base much, but that happens in baseball. Today's a new day," Choo said before Sunday's game. "That last at-bat, that's just baseball. I hit it, [Freese] already caught the ball."

Choo was aggressive in four plate appearances against Cardinals starter Kyle Lohse, swinging at the first pitch in two of those at-bats. The 29-year-old Choo is batting .423 (11-for-26) this season when swinging at the first pitch, and just .095 (2-for-21) when he falls behind 0-2 in counts.

"We don't want to miss the fastball," Choo said. "Lots of out pitches, changeups, sliders [later in the count]... you don't want to see, so that's what I do."

Smoke signals

• Acta said third baseman Jack Hannahan, who's been on the 15-day DL since May 27 with a left calf strain, will likely begin a rehab assignment next week. Acta said Hannahan will play with whichever Minor League club is most convenient at the time, and will likely play four or five games.

• Weekend games have not been kind to the Indians this season. Last night's loss dropped the Tribe to 8-11 in weekend contests. Cleveland is 7-12 on Saturdays, 4-6 on Sundays and 24-15 playing on weekdays.

• The Kent State University baseball team, which features Nick Hamilton, the son of Indians' play-by-play announcer Tom Hamilton, will play the University of Oregon on Sunday for a trip to Omaha for the 2012 College World Series. The No. 13 Shockers defeated the No. 8 Ducks, 7-6, on Saturday in Game 1 of a three-game series. Hamilton, a designated hitter drafted by Cleveland in the 35th round of the MLB First-Year Player Draft this year, went 1-for-4 in the victory. "Tom must be flying," Acta said on Sunday.