With the incumbent Heisman Trophy winner — Oklahoma quarterback Jason White — returning, the preseason pick for Big 12 Conference offensive player of the year ought to be a lock.

But is it?

White has had a history of injuries and, even more important, he’s hardly a Hummer in a field of mountain bikes. The Big 12 is bursting with offensive talent.

Kansas State pinball running back Darren Sproles scooted for 1,986 yards on 306 carries and 16 touchdowns in 2003 and has already been touted for the Heisman should White falter.

White, in fact, may not be the best all-around quarterback in the league. Missouri’s silky smooth Brad Smith rushed for an average of more than 100 yards a game last season and scored 18 touchdowns. If MU has a breakthrough season, Smith conceivably could attract Heisman consideration.

Another possibility is Texas running back Cedric Benson who ran for 1,306 yards and 21 touchdowns last season.

Moreover, you can’t rule out whoever plays quarterback for Texas Tech. Coach Mike Leach’s system seems to turn out a prolific passer every year — first Kliff Kingsbury and then B.J. Symons who threw for nearly 6,000 yards as a senior last season while leading the nation in total offense.

Nebraska’s Joe Daily has to be considered a dark horse. Under first-year coach Bill Callahan, the Cornhuskers moth-eaten I-formation is expected to be replaced by a wide-open, pro-style passing attack with Daily at the controls.

Colorado quarterback Joel Klatt also has an outside shot after throwing for 2,614 yards and 21 TDs last season, but the Buffaloes’ may wobble under a cloud of off-season allegations.

Here’s a look at the Big 12 Conference by divisions:

NORTH

Colorado

The ongoing joke is that more CU games will be on Court TV than on network television. Colorado faces federal lawsuits by three women who say they were raped after a 2001 off-campus party attended by players and recruits. A grand jury is also investigating allegations of whether a former recruiting aide hired prostitutes for recruits.

And if the allegations weren’t enough, five players have transferred in the wake of the scandal. Three were returning starters — running back Brian Calhoun, cornerback Sammy Joseph and defensive end Marques Harris. Calhoun was the Buffs’ leading rusher last season with 810 yards.

Regardless, the Buffs need to make giant steps on defense after surrendering 33.2 points and 432.1 yards per game last year.

Iowa State

Following back-to-back bowl seasons, the bottom fell out on ISU coach Dan McCarney last season, mostly because the Cyclones’ offense didn’t measure up to Big 12 standards. Only Baylor compiled fewer yards.

So McCarney hired Barney Cotton, late of Nebraska, as his new offensive coordinator and immediately announced: “The first thing we want to get back to doing is running the football. Our goal is to be one of the top rushing teams in the conference.”

Actually, the Cyclones’ defense wasn’t so hot, either, but six of the front seven return so if experience counts improvement is possible. More good news: Baylor returns to the ISU schedule this season while Texas and Oklahoma disappear.

Kansas State

Never discount a Bill Snyder team even if it loses 30 seniors. The Wildcats just win, baby. Who can forget last year’s shocking 35-7 romp over Oklahoma in the Big 12 title game?

Snyder does have a quarterback question, and the defense has holes to fill, but Snyder seems to produce a skilled QB perpetually and K-State usually ranks in the Top 10 nationally in total defense.

Then there is Sproles, arguably the best running back in the Big 12. K-State ran about twice as much as it passed last season and it’s not inconceivable Snyder would opt for at least a 3-to-1 rush-to-pass ratio this fall.

Missouri

Tigers won eight games for the first time since 1980 and Gary Pinkel is the toast of the Show-Me State. Seven of the eight wins were in Columbia, so Mizzou must now prove it can win on the road.

Junior quarterback Brad Smith leads a rushing offense that led the Big 12 and finished sixth nationally. Only Nebraska, however, has a less productive passing game.

Missouri benefitted from having a league-low 13 giveaways in 13 games. In two years, Smith has been intercepted only 13 times in 716 attempts. The Tigers were also the least penalized team in the league (47 yards a game).

Senior linebacker James Kinney was fourth in the league in tackles (144), but overall defense was only so-so. The punting game needs an upgrade.

Nebraska

The Cornhuskers won 10 games last fall, but they lost three (at Missouri, Texas and Kansas State) so coach Frank Solich, a protege of living legend Tom Osborne, was dispatched in favor of Bill Callahan, late of the NFL’s Oakland Raiders.

How good the Huskers will be on a weekly basis remains to be seen, but they should be great on a Daily basis as Callahan puts the QB job in the hands of Joe Daily who is not a tailback playing QB as Jammal Lord was.

Daily threw 16 passes in the first quarter of the spring game — a mere 61,000 showed up, by the way — and that was one more pass than NU averaged in an entire game last year.

Air Nebraska? Who would have thought it?

SOUTH

Oklahoma

Until running afoul of Kansas State in the Big 12 title game, then bowing to LSU, 21-14, in the Sugar Bowl, Oklahoma was regarded as a team destined for immortality.

Now with Heisman Trophy winner Jason White back for a sixth year, the Sooners should have the wherewithal to prevent another Smarty Jones finish this season.

White is just one of 10 starters back from an offense that ranked third in the nation in scoring last year. Wide receiver Mark Clayton is the league’s most dangerous receiver and touted recruit Adrian Peterson should juice the running game.

OU’s defense has to reload a bit, but coach Bob Stoops always has plenty of ammo stockpiled.

Oklahoma State

Hey, these guys were good. A three-point loss to Mississippi in the Cotton Bowl did little to diminish a nine-win season that featured a win over Kansas State.

However, coach Les Miles must replace Rashaun Woods, the league’s leading receiver, and Tatum Bell, the Big 12’s second-leading rusher. Woods’ younger brother D’Juan is heir apparent at wide receiver and junior Vernand Morency, who riddled Kansas for 269 yards and three TDs, is Bell’s likely replacement.

Filling the shoes of quarterback Josh Fields may not be quite as easy. Fields, the school’s career TD passes leader with 55, signed a pro baseball contract with the Chicago White Sox in June. Fields, who had one year of eligibility remaining, was the 18th player selected in baseball’s free agent draft. Freshman Bobby Reid is his probable replacement.

Not to be overlooked is Oklahoma State’s enviable kicking game. Senior Cole Farden averaged 43.2 yards per punt last season while Luke Phillips nailed 16 of 18 field-goal attempts.

Texas

Coach Mack Brown lost 19 seniors off a squad that won 10 games, but will be remembered mostly in the Lone Star State for its record 65-13 flogging by Oklahoma in the annual Red River Rivalry.

Among the notable Longhorns returning are senior Cedric Benson, the only running back to rush for 1,000 or more yards each of the last three seasons; quarterback Vince Young, the Big 12 Freshman of the Year; and Derrick Johnson, who is generally regarded as the best pro prospect linebacker in the country.

Another fine herd of Texas cattle.

Texas A&M

Dennis Franchione suffered through a 4-8 Aggie joke during his first season in College Station, mainly because the vaunted A&M band was more proficient than his defense. The Aggies dropped eight of their last 10, defeating only Baylor and Kansas, both at home.

Guess which Big 12 team surrendered the most points last fall. Iowa State? Nah. Baylor? Nope. It was A&M. The Aggies also ranked last in rushing defense. Well, at least Franchione knows his woes.

The good news is the offense isn’t bad. Reggie McNeal emerged as a talented quarterback and soph Courtney Lewis became the first Aggie running back to gain more than 1,000 yards since 1998. McNeal had surgery on his throwing shoulder over the winter, but is expected to be ready for the season opener after missing spring practice.

Texas Tech

Two years ago, coach Mike Leach lost Kliff Kingsbury, who set 17 NCAA passing records and tied three others. This year he loses B.J. Symons who shattered Ty Detmer’s NCAA record when he tossed for 5,833 yards.

Who’ll be the next quarterback plugged into Leach’s pass-always system? Most likely, it’ll be Sonny Cumbie, a 6-foot-4, 210-pound senior. Whoever it is will find ample targets — particularly Taurean Henderson who caught a freshman-record 98 passes last season.

Disquieting note: Texas Tech led the nation is passing and total offense last season, but the Red Raiders gave up more yards than any other Big 12 team.

Baylor

Kermit the Frog was right. It isn’t easy being green. The Bears opened conference play last season with a stunning 42-30 win over Colorado, then dropped their last seven. Baylor has now played 32 Big 12 games on the road and won zero. This year’s league road trips are to Nebraska, Texas, Texas Tech and Oklahoma State so coach Guy Morriss can probably mail in an 0-36 league road record.

Baylor does boast a quality punter in Daniel Sepulveda who made a league-high 87 punts for a 43.1 average — third best in the Big 12. The Bears also have an underrated free safety in junior Maurice Lane.