CHICAGO -- The Cubs likely began their last series of 2012 against a contender Friday afternoon, as the Cardinals -- one of the National League Wild Card leaders -- came to Wrigley Field.

After this weekend, Chicago closes the season with three games each against the Rockies, D-backs and Astros. Only the D-backs, with a 5 1/2-game deficit in the Wild Card, are mathematically still alive for the postseason.

Without the fortunes of other contending teams hinging on the outcome of games against the Rockies and Astros, Cubs manager Dale Sveum said Friday he will use his bench more than he has the past two months, giving even more guys opportunities.

"No doubt about it," Sveum said. "You'll change it up a bit."

That goes for the bullpen, as well as the lineup. Part of the reason is because two of the club's go-to relievers are at, near or already have surpassed career highs.

Right-hander Shawn Camp has matched his career high of 75 appearances and is 6 2/3 innings shy of the highest workload of his career.

Lefty James Russell already has worked in a career-high 71 games, and he's 4 1/3 innings from establishing a new high in that category.

Sveum said the Cubs would like to only use Camp and Russell in games they're winning, giving others ample opportunity to contribute.

"We don't want [their workload] to go any higher when we're losing baseball games," Sveum said. "We'll get enough looks at the all these guys in these next 12 games."

Barney's bat overshadowed by errorless streak

CHICAGO -- Conversations about Darwin Barney always come back to the Cubs second baseman's defense.

And as Barney entered Friday with his National League record of 135 straight errorless games still intact, his offensive improvement during the season's second half -- especially this month -- hasn't received as much publicity.

Barney is hitting .277 with a .380 on-base percentage and .706 OPS since the All-Star break. In 19 September games, those marks have risen to .348/.419/.810.

Barney's on-base percentage this season (.314) is similar to last season (.313), but Cubs manager Dale Sveum said Barney's recent improvement in that area might be best explained by going through the maturation process, like every young player.

"Everybody wants young guys to have on-base percentage, and it doesn't come until you've had your 2,000 at-bats in the Majors Leagues or 4,000 at-bats in professional baseball," Sveum said. "Everybody's a little bit different, but the scale of on-base percentage is not brought up by one-year players and 22-year-old kids. That's not where it usually happens at."

Barney, 26, has a little more than 1,000 Major League at-bats and about 3,200 professionally, so he is getting there. The second-year player is doing it while also by proving his worth defensively, as he sits six games shy of tying Placido Polanco's Major League record of 141 straight errorless games by a second baseman.

"Obviously, we want the OPS to be over .700, but that kind of defense is saving runs constantly every single day," Sveum said.

Worth noting

• With 103 RBIs, left fielder Alfonso Soriano entered Friday one shy of his career high of 104, set in 2005 with Texas.

• Cubs batters entered Friday having drawn 213 walks in 65 games (3.3 per game) following the All-Star break, after averaging 2.3 walks per game in the first half. The club has drawn at least five walks in five of its last 10 games.

• The Cubs, HMSHost and the Chicago Department of Aviation have joined forces to introduce the Cubs Bar & Grill in Terminal 3 of O'Hare International Airport.

The restaurant is a customized sports bar that will offer items served at Wrigley Field, in addition to a wide variety of other options. The grill will have a replica of the Wrigley Field Marquee and various Cubs memorabilia throughout.