© 2013 MLB Advanced Media, L.P. All rights reserved.

8/19/2013 7:51 P.M. ET

Polanco placed on seven-day concussion DL

MIAMI -- Still woozy a couple of days after being struck on the helmet by a pitch, the Marlins on Monday placed Placido Polanco on the seven-day concussion disabled list.

Initially, Polanco was hopeful he didn't have concussion-like symptoms. But after being re-examined on Sunday, the decision was made to shut him down for at least a week.

"Polanco was diagnosed with a concussion," Miami manager Mike Redmond said. "He's going to go on the seven-day DL. We were, obviously, hoping that wasn't the case. But the next day he realized it was a little bit more severe, and he did have a concussion."

Replacing Polanco is Gil Velazquez, who had his contract selected from Triple-A New Orleans. To free up 40-man roster space, Marcell Ozuna was transferred to the 60-day disabled list.

"Gil has been around a long time, and he can do a lot of different things," Redmond said. "The biggest thing is we do not have to play a man short for a couple of more days."

In the eighth inning on Friday night against the Giants, Polanco was plunked on the left side of his helmet by Santiago Casilla's 94-mph fastball.

On Saturday, Polanco was upbeat and said he was feeling substantially better. He didn't have a headache, but he admitted to feeling a little dizzy.

It's too early to tell if Polanco will need more time than a week.

"It's hard to tell," Redmond said. "When you're dealing with concussions, those things are so serious. It's a matter of waiting and seeing. We will see how he feels the next five or six days."

Polanco, 38, has split playing time at third base with Ed Lucas.

In 91 games, Polanco is batting .253.

Velazquez, 32, is in his second stint with the Marlins. A year ago, the utility infielder appeared in 19 games with Miami in the second half.

Velazquez was batting .275 in 67 games with New Orleans.

Ozuna is out for the season after undergoing surgery to his left thumb.

Fernandez closing in on innings limit set by Marlins

MIAMI -- Each inning brings Marlins right-hander Jose Fernandez closer to the end of his thus far remarkable rookie season.

Before the season, Miami management set a range with the maximum of about 170 innings.

Fernandez entered his 24th start against the Dodgers on Monday night at Marlins Park at 139 2/3 innings.

No firm date has been set.

But basically, the club is projecting its shut-down date based on an average of seven innings per start. If he indeed can go seven innings per outing, his final start would be on Sept. 4 against the Cubs at Wrigley Field. That's if the Marlins go with him every fifth game from this point forward.

At seven innings per start, he would reach 167 2/3 on Sept. 4. If the club decided to give him an extra day, he could finish up on Sept. 6 at Marlins Park against the Nationals.

"We set that deadline for a reason," Miami manager Mike Redmond said. "It's to take care of him and protect him. We realize this is a special kid who we want to keep healthy and have pitch for a long time."

Fernandez has enjoyed a terrific season, pacing rookie pitchers with at least 15 starts in ERA (2.45), opponents' batting average (.190) and strikeouts (149) entering Monday.

Fernandez is on pace to break the Marlins' rookie strikeout mark of 166, set by Scott Olsen in 2006.

The hard-throwing right-hander -- along with Dodgers outfielder and fellow Cuba native Yasiel Puig -- is a strong National League Rookie of the Year Award contender.

"When you set that deadline in Spring Training, you don't know how that's all going to shake out," Redmond said. "He's gone out and pitched great. For him to be in the situation he's in is tremendous.

"At the same time, too, I don't think guys always focus on the awards. They focus on doing their job. When they do their job, they're rewarded with accolades -- Rookie of the Year, MVP or whatever it is."

Fernandez's story is well documented.

He made the leap from Class A to the big leagues at the start of the season. He logged 134 innings in the regular season in the Minor Leagues a year ago.

In 2012, Fernandez made his last start during the championship round of the Florida State League playoffs on Sept. 9. He worked five innings that day in Class A Jupiter's victory over Lakeland.

"He's definitely done his job," Redmond said. "If I had to pick, I'd pick him [Rookie of the Year], for sure. But he's definitely at a disadvantage when you're talking about the Dodgers and the Marlins. For us, he's definitely our Rookie of the Year."

Stanton, Marlins can learn from series vs. Dodgers

MIAMI -- All signs point to a mismatch as the Marlins face the Dodgers in a four-game series this week at Marlins Park.

The Dodgers are loaded with proven, marquee-named talent. The Marlins are inexperienced and going through growing pains.

What can the Marlins learn from this series?

"We can learn if we can play with these teams," Giancarlo Stanton said. "You've got to beat them to show we can compete with them. The Giants kind of kicked our [tails] a little bit this weekend. But we got them at their place, which is usually harder to do on the road."

The Marlins dropped two of three over the weekend to San Francisco. Now the Dodgers, who are on a historic run, are steamrolling into South Florida. They've won 42 of their last 51.

"Are you going to show up today or not?" Stanton said. "Maybe if we whup on them one or two of these four, you know that we can compete with a team that has never been hotter in the history of the game."

Stanton came up with a key defensive play in the ninth inning in Sunday's 6-5 win over the Giants. With one out, Hector Sanchez singled to right, and Stanton cut the ball off before it reached the wall, which would have led to extra bases.

By keeping the runner at first, closer Steve Cishek got Buster Posey to tap into a game-ending, 6-4-3 double play.

"Little things," Stanton said. "Little big things, and for 27 outs. You can't get up for six innings, and let down. They're going to come back on you if you do."

Joe Frisaro is a reporter for MLB.com. He writes a blog, called The Fish Pond. Follow him on Twitter @JoeFrisaro. This story was not subject to the approval of Major League Baseball or its clubs.