Despite the injury, Bryce is listed as day-to-day, and might play in Saturday's game against Northwestern State.
Petty, considered a preseason contender to win the Heisman Trophy, left at halftime of Baylor's 45-0 victory over SMU on Saturday. He completed 13 of 23 passes for 161 yards. When Petty left, he was grabbing his left hip.
An MRI revealed the two cracks on Monday
"I'm bummed out because it's never fun being hurt," Petty told CBSSports.com. "Bummed out because I just watched tape and everything is off. You never want to make any excuses. When you're throwing and I can't torque [it's frustrating]. Every time I went to throw it would jolt. It felt like somebody was punching me in my side."
FOXSports.com reported that Petty's injury is the kind that heals on its own. It becomes a matter of whether he can handle the pain in determining whether he can play.
Head coach Charlie Strong told reporters Monday that Ash took a hit during the first quarter of Texas' 38-7 win over North Texas, and appeared fine. Texas trainers then received a call from Ash in the middle of the night. Strong said that some of the post-game symptoms Ash exhibited were headaches and dizziness.
Ash missed 10 games last season and received a medical redshirt after suffering a concussion at BYU last season.
Strong said no official determination has been made about how long Ash will be sidelined or if he will play again this season.
"Anytime you have that number of concussions, you have to be concerned," Strong said. "You're always concerned about a young man's health, and we would never jeopardize a young man's health just for this football team. Players' health is always first."
Sophomore Tyrone Swoopes will start for Texas (1-0) against BYU (1-0) on Saturday. Swoopes, who was beat out by Ash in camp, played six games as a true freshman in 2013, completing five passes for 26 yards and running 20 times for 79 yards. True freshman Jerrod Heard will be his backup.
Strong also announced Monday that center Dominic Espinosa, a 40-game starter, fractured a bone in his right ankle and would have season-ending surgery Wednesday.
Espinosa went down in the third quarter Saturday and had to be carted to the locker room. Redshirt freshman Jake Raulerson, who replaced Espinosa in the game, is expected to become the starter.
---Alabama defeated West Virginia in a hard-fought 33-23 victory at Atlanta, but the win came at a cost, coach Nick Saban said.
Senior defensive back Jarrick Williams fractured his foot and will miss at least four weeks. Williams has started 10 games in his career.
Another senior, wide receiver DeAndrew White, has a separated shoulder and is expected to miss two weeks. White made six receptions for 73 yards.
Saban also said he isn't sure which of his quarterbacks will get the start or how they will share the reps Saturday against Florida Atlantic. But he did commit to playing both players.
"When I figure it out, I won't tell you," Saban said with a smile.
---Florida State coach Jimbo Fisher lifted wide receiver Jesus "Bobo" Wilson's indefinite suspension.
Wilson missed the Seminoles' season-opening 37-31 victory over Oklahoma State on Saturday night, although he traveled with the team and dressed for the game.
Wilson will be eligible to play against The Citadel this Saturday.
---Iowa State receiver Quenton Bundrage's season lasted all of four plays.
The school announced that the Cyclones' top receiver from last season tore an ACL in Saturday's loss to North Dakota State and will miss the rest of this season.
Bundrage led the Cyclones in receiving in 2013 with 676 yards and nine touchdowns.