Tony DeMarco

First on the North Side, and then on the South, the battle for Chicagoland supremacy will unfold over the next two weekends.

And for a change, both rounds of the so-called Cross-town Classic will have relevance all around the game.

This time, everybody’s attention should be fixed on the Windy City, because home-and-home series at Wrigley and U.S. Cellular will involve two first-place teams playing with it’s-this-year mind-sets.

Starting Friday, it will be the team with the game’s best record vs. the team with the fifth-best mark and tied for the biggest division lead. Nobody is about to say this is a potential World Series preview, but who doesn’t think both could be playoff-bound?

Not that both the Cubs and Sox aren’t without concerns heading into the showdown. But at this point, they are only concerns — not reasons for panic — not when there is so much to like on both sides of town:

Cubs
Before too much consternation is caused by the broken bone in Alfonso Soriano’s hand and Carlos Zambrano’s sore shoulder that still is being evaluated, consider this about the Cubs:

They easily have the best home record in the league (28-9).

They easily have the biggest positive run differential in the majors (+101 runs), and only the Phillies (+90 runs) among NL teams are within 60 runs of that figure.

Take your pick from among the Cubs’ two possible Rookie of the Year Award winners: Geovany Soto is the runaway leader behind the plate in All-Star Game voting, and is first or second among NL catchers in home runs, RBIs, on-base and slugging percentage.

Kosuke Fukudome trails only Soriano in the All-Star outfield balloting, his combination of skills making an undeniably positive difference.

The Cubs were near the bottom last season in on-base percentage. Now they are at the top with much the same personnel, Fukudome being the biggest reason why. He has hit all over the lineup, and will settle in at leadoff until Soriano’s return, and his defense is Gold Glove-caliber.

Other than John Smoltz, who’s been better at going from closer to starter than Ryan Dempster? Kerry Wood is succeeding in the closer role well enough to hold off the best reliever in the game who isn’t a closer — flame-thrower Carlos Marmol. Check out Marmol’s dominance: 43 innings, 18 hits, 63 strikeouts, .126 opponents batting average, three saves, 20 holds.

Soriano hopes to be back for the All-Star Game; Zambrano’s loss would be manageable in the short-term, especially with NL Central competition anything but overwhelming. In case you hadn’t noticed, St. Louis has been playing without Albert Pujols, and Yadier Molina also is hurt, along with a handful of pitchers. The Milwaukee Brewers have their issues, as well, and the Pittsburgh Pirates, Houston Astros and Cincinnati Reds trail by double-digits.