WACO, Texas (AP) Baylor quarterback Bryce Petty has two cracked small bones in his back.
Petty had an MRI on Monday, a day after taking an early shot to his back and playing only the first half of the 10th-ranked Bears' season-opening 45-0 win over SMU.
The diagnosis was two cracked transverse processes, small bones that stick out from each side of a vertebra.
Coach Art Briles said during the Big 12 coaches teleconference that the reigning Big 12 offensive player of the year is day to day.
Baylor, which didn't practice Monday, is home Saturday night against Northwestern State.
Petty was hit in the back on his first series Sunday night. He still threw for 161 yards and two touchdowns, and added a 5-yard TD run for a 31-0 halftime lead.
The quarterback was clearly in discomfort, often clutching at his lower back. He grimaced and was slow getting up after taking a shot going into the end zone on his scoring run, but played two more series after that.
While he was 13-of-23 passing, Petty uncharacteristically missed open receivers on several throws he usually completes. Petty threw for 4,200 yards with 32 touchdowns and three interceptions last season, when he completed 62 percent of his passes.
''I was battling through some stuff that whole first half. I couldn't really plant and throw as well as I wanted to,'' Petty said after the game. ''Every time I planted, I could feel it.''
Petty insisted he was already feeling a lot better after the game and could have played more if needed.
''It's nothing that serious,'' he said. ''Everything's good.''