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8/23/2013 12:35 A.M. ET

Polanco being monitored after concussion

MIAMI -- Marlins infielder Placido Polanco continues to be monitored every day as he remains on the seven-day concussion list.

Polanco, who was hit on the helmet by a pitch last Friday against San Francisco, has been riding a stationary bike at Marlins Park the last two days.

"We're not going to rush him or push him or anything," Marlins manager Mike Redmond said. "It's all going to rely on how he feels from day to day and how we progress. We're going to take it slow. There's no reason to rush him."

Redmond went on to applaud Major League Baseball's concussion protocol, mandatory steps that are taken in order to maintain player safety.

"[Concussions are] happening more frequently," said Redmond, who was a catcher for 13 years in the big leagues from 1998-2010. "I remember from the time I played there really wasn't anything. I think that's great, that it's obviously become a big issue and making sure that guys get onto the field when they're ready and well and healthy.

"These guys are in great hands. The doctors were evaluating immediately with Polanco. He was with the doctor, and they evaluate him and keep an eye on him and close tabs."

Marisnick still waiting to find his groove

MIAMI -- Jake Marisnick found himself back in center field and hitting seventh in the order for Miami's series opener against the Rockies on Friday night after his third day off since he was called up on July 23.

Through 27 games entering Friday, the 22-year-old -- who is the team's second-ranked prospect behind outfield mate Christian Yelich -- was hitting .182 with one double, one home run and four RBIs.

But in Friday's 3-2 loss to the Rockies, Marisnick hit his first career triple as part of a 1-for-4 night, and scored on Greg Dobbs' sac fly.

"The way it's been going [with me] struggling a little bit -- it's no secret -- I think it was to give me the day to relax and get my thoughts together and get back out there and get me in a groove," Marisnick said.

Marisnick, who missed the first month of the Minor League season with a broken hand, said he experienced similar difficulties during his time in Double-A.

This May, he hit .248 with six home runs and 24 RBIs, but wrapped up his stint with Double-A Jacksonville batting .294 with 12 homers and 46 RBIs, leading to his promotion.

"I've done it at every level I've been at once I'm called up. I don't know if it's when I first get there I try to do too much and I lose focus of what I've been trying to do," Marisnick said. "I think that has something to do with it.

"I came up here wanting to hit home runs and got my swing pulling off the ball and trying to do too much. I think over time it won't be a big problem."

Marlins end stretch against tough lefties

MIAMI -- As the Marlins close out their 10-game homestand against the Rockies this weekend, so ends a stretch in which the team faced four left-handed starters in its last five games.

It began on Sunday, when San Francisco's Madison Bumgarner took the mound. Los Angeles then pitched Hyun-Jin Ryu, Chris Capuano and Clayton Kershaw during a four-game set.

Miami split those matchups, winning the first two while dropping the final two. In the 25 1/3 innings those four pitched, the offense scored 10 runs -- nine earned.

Entering Friday, the Marlins had the lowest batting average (.227) of all big league teams, just behind the Nationals (.228), and the third fewest runs scored (114) against southpaws.

The Marlins didn't face a lefty starter in Friday's 3-2 loss to the Rockies, but Colorado's lefty closer Rex Brothers pitched a 1-2-3 ninth inning with two strikeouts.

"Statistically, we haven't done really well against left-handed pitching, but I thought despite losing three out of four to the Dodgers we swung the bat all right," Marlins manager Mike Redmond said. "We didn't get a ton of hits in those games, but I thought even with [Zack] Greinke, we swung the bat really well. We just didn't get a whole lot to show for it."

Redmond believes his team had a good approach -- pointing to several long outs and line drives the offense couldn't capitalize on. With several rookie starters, the offense continues to be a work in progress.

"Offensively, we have some challenges there and left-handers have been a bigger challenge than righties," Redmond said. "Guys' approaches have been solid, and I think as we face more and more lefties down the road we'll continue to get better."

Worth noting

• The Marlins announced Miami Children's Museum as an official charity partner, one of four non-profit organizations to receive this recognition. The Marlins donated a $25,000 gift to support Sensory Saturday -- a monthly inclusive and accessibility program that allows children with special needs and their families to explore the museum and its exhibits in a sensory modified and supportive environment.

Christina De Nicola is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.