Joe Gibbs Racing was found to have oil pans that were never submitted for approval on all three of its Sprint Cup cars at Michigan International Speedway, according to SPEEDTV.

JGR had to pull the engines and replace the pans. Kyle Busch was behind the wheel of his No. 18 Toyota at the start of practice, indicating that he was almost ready to head onto the track.

Denny Hamlin’s No. 11 Toyota is still being worked on, so he is not yet ready for practice. Joey Logano’s No. 20 Toyota was even further behind the No. 11.

They could face penalties. Any penalties would be announced early next week.