Updated

NORMAN, Okla. (AP) Oklahoma quarterback Baker Mayfield left Texas Tech on bad terms two years ago.

That will be in the back of his mind Saturday when he faces his former team for the first time.

Mayfield walked on as a freshman and opened the 2013 season as Tech's starter, but lost the job later in the season. Despite being named Big 12 Offensive Newcomer of the Year, he had no scholarship offer on the horizon, and so he transferred to Oklahoma.

Texas Tech wouldn't allow Mayfield immediate eligibility after his transfer, which bothered Mayfield since he was never on scholarship at Tech.

''It's human nature to try and get revenge,'' Mayfield said. ''That's just how everybody works, but I've got to focus on doing my job and my job only, and that's going out and executing my stuff and helping our team win. That's what I'll be focused on this week.''

Mayfield's transfer has worked out. He's among the nation's leaders in passing yardage, passing efficiency and total offense for the 17th-ranked Sooners (5-1, 2-1 Big 12).

Tech coach Kliff Kingsbury said too much has been made of the situation. He'd rather focus on the fact that his Tech team (5-2, 2-2) could win its third straight conference game.

''That happened two years ago really, 21 months, something like that,'' he said. ''It's two good football teams. I don't want to take away from that based on that story line. So I'm excited to watch those two teams go at it.''

Here are some other things to watch for Saturday's game:

MIRROR IMAGES: Both teams use the Air Raid offense, which means the game could last a while. Texas Tech averages 82 plays per game, while Oklahoma averages 76. Only Bowling Green has run more plays this season than the Red Raiders.

RUNNING ROOM: Tech's DeAndre Washington is among the Big 12's leaders with 107 yards rushing per game. Oklahoma's Samaje Perine averages 70 yards per game, but he ripped the Red Raiders for 213 yards and three touchdowns last season, and Oklahoma still leans on him at times. Both teams need some degree of balance for their pass-heavy systems to work best. Tech's Justin Stockton and Oklahoma's Joe Mixon are backups who are dangerous in both the running and passing games.

STRENGTH vs. STRENGTH: Texas Tech QB Patrick Mahomes ranks third nationally in total offense and yards passing per game. Oklahoma ranks ninth nationally in pass defense. Oklahoma cornerbacks Zack Sanchez and Jordan Thomas have combined for five interceptions in three Big 12 games, and the unit has surrendered just 91 yards passing per league game. Mahomes will need to be careful against a secondary that is much more aggressive than last year's group.

TECH'S DEFENSE: Tech has allowed 553.6 yards per game and ranks 122nd out of 127 FBS teams in total defense. Its defensive numbers are even worse in Big 12 play - the Red Raiders are surrendering a mind-blowing 600 yards per game - 268.8 on the ground and 331.2 in the air - during league play. Oklahoma's offense is formidable, ranking 18th nationally in yards per game (488.8) and 13th in points per game (40.0).

FRANK SHANNON: With Oklahoma linebacker Jordan Evans likely out with a left leg injury, Shannon is expected to get his first start of the season. Shannon was suspended last year for a violation of the school's Title IX policy, which covers sexual misconduct. Shannon was Oklahoma's leading tackler in 2013. Evans took the job last season after Shannon's suspension and held onto it during preseason camp.

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AP college football website: www.collegefootball.ap.org