Park did not travel with the rest of the team as they prepare for a road game against the No. 3 Oklahoma Sooners.
Park didn't make the trip to Norman, Okla., and coach Matt Campbell doesn't have a timetable for his return.
But the player of the game might have been Joel Lanning, who played LB and QB for the Cyclones.
After sitting out a season - and playing church league flag football to stay in shape - Park transferred to Iowa State last season.
The redshirt junior has thrown for 1,181 yards, nine touchdowns, and five interceptions on the year.
Iowa State: The Cyclones, heavy underdogs, didn't need tricks or a slew of takeaways to beat the Sooners. The Cyclones couldn't reach the endzone, but Garrett Owens crushed a 42-yard field goal to get the Cyclones on the board in the second half. Iowa State got back into the game with 21 straight points to take the lead after falling behind 24-10.
The Sooners moved 72 yards on 11 plays in their second series, scoring on a 15-yard Mayfield to CeeDee Lamb pass. Lamb was injured on the play and seen without his helmet and shoulder pads on the OU bench with ice on his left shoulder. Though Oklahoma's offense purred as usual, the defense struggled against a team that scored just seven points against Texas with Park. The defense that looked dominant in nonconference play has been leaky during Big 12 action. The last two open dates for the Big 12 are this week, with 15th-ranked Oklahoma State and winless Baylor not playing.
Oklahoma: Plays Texas in Dallas on Saturday.