The 20th Annual Arnold Motor Supply 360 Knoxville Nationals starts this Thursday. However the last two champions, Wayne Johnson in 2008 and Terry McCarl in 2009 will not be racing. Both have suffered serious leg injuries in the last few weeks. Johnson shattered his leg and dislocated his ankle in a crash in Washington. He is home recuperating. McCarl broke both his Tibia and Fibia at Husets Speedway last week. According to his wife Lori, T-Mac had another surgery today to do skin graphs. She adds he should be able to be released from the hospital today.