I may be a tad harsh on Brunson, and although I usually appreciate fighters who take up fights on short notice, Brunson should never have taken that fight knowing his cardio was subpar. He was on a two fight losing streak, and losing to Leben in his UFC debut would most definitely get him cut from the UFC. He should have known better. Whats the point of being a good company man and taking up short notice fights if he is gonna look horrible and negate all the good he has done in Dana's eyes? Look at what happened to DeMarques Johnson.
Good for Brunson that he got the win. Would prefer him to actually work on his cardio problems before he returns to the cage though. Middleweights shouldn't be struggling with cardios like heavyweights do. That fight against Leben could have given a conditioned middleweight a huge opportunity to rise up the ranks by dismantling Leben. Leben looked absolutely terrible.
Brunson likely took the fight because he was on a two fight skid and his being brought into the UFC was far from a forgone conclusion.