Who tops Doug Haller's preseason Pac-12 poll?

This season’s Pac-12 South is expected to be one of the toughest divisions in the country.

When the preseason media poll comes out next Thursday, there’s a good chance four of the six teams - Arizona, Arizona State, UCLA and USC - will receive first-place votes. Those same four likely will kick off the season in the AP Top 25.

My media-poll ballot is in. Here’s how I see this season’s Pac-12 unfolding:

SOUTH DIVISION

1. Arizona State

Eyes rolling over the hometown reporter picking the local team? I get it. (For the record, I’ve picked ASU to win the South only once -- 2013, the year it won.) But here’s the deal: Not much went right for ASU last season. The quarterback missed three games with a broken foot. The defense needed half the season to figure things out -- and the Sun Devils still won 10 games.

RELATED: More ASU football coverage

Don’t worry about the offense. Even with the uncertainty at tackle, this group will score. No, this season’s success depends on the defense. Last year, ASU was average on that side. This season, with nine starters returning, the Sun Devils will be better. And it will get them to the conference championship game.

2. Arizona

Remember last year’s Territorial Cup, the one that decided the South? Good. Because this year’s showdown at Sun Devil Stadium will have similar stakes. The Wildcats return their starting quarterback, leading rusher, leading receiver and the best linebacker in the country in Scooby Wright.

RELATED: More Arizona Wildcats coverage

True, the schedule doesn’t include an off-week, but overall, it’s not bad. UA’s downfall: Final-month road games against USC and ASU.

3. USC

The Trojans are the national favorite and without question, there is much to like. Quarterback Cody Kessler is efficient and the offensive line shapes up as one of the best in the country. Even so, the defense must improve, and that won’t be easy without All-America defensive end Leonard Williams and leading tackler Hayes Pullard.

4. UCLA

The Bruins are loaded everywhere expect for where it matters most -- quarterback. Josh Rosen is expected to win the job. He’s talented, but relying on a true freshman to navigate a division this tough is far from ideal.

5. Utah

The Utes last season won nine games, the first time they have done so as a member of the Pac-12. Duplicating such efforts will be difficult.

6. Colorado

The Buffaloes lost their final eight to end last season, but four were decided by a touchdown or less (two coming in overtime). Mike MacIntyre’s group is improving, but so is the rest of the division.

NORTH

1. Oregon

Once he completes his graduation requirements, Vernon Adams, former star quarterback at lower-division Eastern Washington, is expected to replace Heisman Trophy winner Marcus Mariota. Does he need to be great? Not with Royce Freeman and Byron Marshall, two of the Pac-12’s top playmakers, around him.

RELATED: Pac-12 football schedules for 2015

2. Stanford

The Cardinal last season failed to reach double-digit wins for the first time in five years. Fluke or something more serious? Go with the former. Stanford is reloading defensively, but still should have enough to hold down second place.

3. California

The Golden Bears have the Pac-12’s best quarterback in Jared Goff, but their schedule – with road games at Texas, Utah, UCLA, Oregon and Stanford – is scary.

4. Washington

The Huskies -- ninth in conference scoring last season -- should be better offensively, but their defense suffered significant losses with four players selected among the NFL draft’s first 44 picks. They may take a step back.

5. Washington State

This is Year 4. Coming off a disappointing season, Mike Leach and the Cougars don’t need to contend in the North, but they need to be a factor. The entire offensive line returns, but much will depend on first-year quarterback Luke Falk.

6. Oregon State

New coach Gary Andersen will win -- probably sooner rather than later -- but with a new quarterback and an inexperienced defense, he has some rebuilding to do.

Contact Doug Haller at Doug.Haller@arizonarepublic.com or at 602-444-4949. Follow him at Twitter.com/DougHaller.