The White Sox, as CBSSports.com colleague Jon Heyman wrote today, have prioritized starting pitching in trade talks this week, with Zack Greinke the top target.

The surprising White Sox are hoping to hold off the Tigers . . . who also have decided to make starting pitching a top priority, according to sources. It's not yet clear what pitcher tops the Tigers' wish list, but they have been linked to the Cubs (Matt Garza, Ryan Dempster) and are also known to have interest in James Shields.

Why a pitcher and not another hitter, or a second baseman?

Well, first off, chasing a pitcher doesn't mean the Tigers are ignoring the second base issue. They have watched Marco Scutaro of the Rockies, and would be interested in Omar Infante if the Marlins are willing to move him.

But pitching has become a major concern, because of this simple question: After Justin Verlander, which Tiger starter would you feel comfortable starting in Game 2 of a postseason series?

While the Tigers still need to get to the postseason, they've been clear all along that success this year would be winning in October, not simply getting there. Any second baseman they could possibly acquire now is less likely to be an October difference-maker than a top starting pitcher would be.

The Tigers had hoped they had a solid top of the rotation, but the first half of this year has raised concerns about Doug Fister (who hasn't been as healthy or consistent as he was last year), Max Scherzer (inconsistent) and Rick Porcello (mostly disappointing). The Tigers will turn to prospect Jacob Turner this week to fill the spot of injured rookie Drew Smyly, but Turner is more likely to be a trade chip to acquire a top-level starter than he is to be the 2012 answer.

The White Sox, despite their 3 1/2-game lead over the Tigers, have even more pressing rotation concerns.

Gavin Floyd has now had to miss a start because of a sore elbow, and John Danks doesn't appear close to returning. The White Sox have relied on the impressive Chris Sale and Jake Peavy, but they have concerns about how Sale will hold up and about whether Peavy can remain healthy.