He was running on fumes after two rounds vs Lee, who was running on fumes in one round. RDA apparently had the best gas tank ever, but was dead vs Khabib. It is not just the gas tank, it is the fact that you fear the takedown so greatly that you don't throw, become tentative, get outstruck like 20:1 as a result and when you are on the ground, you are helpless. Look at the Trujillo fight, where Trujillo could do nothing except just look at the ref like "help me. please. please help me."
This fight is going to be an absolute demolition derby, no different than Barboza or Mj and potentially worse, as Tony is a slow starter, lacks explosiveness like Barboza and MJ and apparently has the brilliant idea of not fighting takedowns vs Khabib fucking Nurmagomedov.