Sorting out White Sox roster

This is how it usually happens …

Major-league teams with little or no realistic chance to contend for the postseason head to spring training with anywhere from 60 to 70 players in tow.

Maybe 15 or 20 enter camp with deserved shots to make the 25-man roster. After that, whichever players perform the best in March find themselves in the big leagues.

This spring, the White Sox are not one of those teams.

That’s typically positive news, and it’s one of the primary reasons the Sox are getting plenty of preseason support to overtake the pesky Minnesota Twins and win the AL Central.

The Sox are going to have 53 players in camp this spring, but 21 roster spots are all but locked up. And if injured starting pitcher Jake Peavy continues making progress, he is going to claim No. 22.

Peavy’s health is the main story line as White Sox pitchers and catchers report to camp on Thursday in Glendale, Ariz.

If the 2007 Cy Young Award winner is able to build up enough arm strength over the next six weeks, Peavy could be ready to go when the regular season opens on April 1 at Cleveland.

If not, the Sox have to decide whether to move Chris Sale from the bullpen to the starting rotation.

“That’s a huge swing with our team,” Peavy said last week after throwing 40 pitches off the mound in San Diego. “If I’m healthy and can get back to doing what I know I can do in the rotation, and we can put Chris Sale in the back of the bullpen, that certainly makes us a deeper and a better team.

“I realize that and I want that to happen. I’m going to try to make that happen, but at the same time we’ve got to be smart about when and where we do things.

“If I’m ready, or close to ready, I’m going to take the mound. But if I do miss a time or two, that’s what it is.”

Here are some other battles to watch this spring:

Third base

Give manager Ozzie Guillen credit for backing each and every one of his potential players.

At SoxFest last month, Guillen said Mark Teahen is in the mix for the starting job at third base this spring.

While everyone else has all but given the job to Brent Morel, who looks like a future Gold Glover, Guillen is obviously trying to keep Teahen’s spirits up.

In reality, Morel is going to be the guy barring injury, and as he showed last season, 43-year-old backup Omar Vizquel can still compete with players half his age.

That leaves Teahen in a tough spot, and he is still owed $10.25 million over the next two seasons.

Here is the likely scenario: Teahen gets traded before spring training ends.

There is bound to be an injury on another team, and Teahen can play third base, second and right field.

As long as the White Sox are willing to eat about half of Teahen’s remaining contract, there should be a taker or two.

Utility players

If he is not traded, Teahen is going to fill one of these projected three openings. The Sox are not going to pay him $5-plus million this year to play at Class AAA Charlotte.

If Teahen is moved, however, that is good news for outfielder Alejandro De Aza and infielder Brent Lillibridge, who can also play center field.

And that leaves converted infielder Dayan Viciedo and nonroster invitee Lastings Milledge to battle for the last spot in the outfield.

Rotation

Let’s assume Peavy is not going to be ready to open the season, and let’s also assume the White Sox decide Sale is their full-time closer no matter what.

There are a few in-house candidates to choose from, and Phil Humber could emerge as the fill-in starter with a strong spring.

If Humber flops, keep a close eye on lefty Charlie Leesman, who was 5-2 with a 2.69 ERA in 11 starts for Class AA Birmingham last season.