he suffered neurological damage after the illegal punch thrown by arthur abraham during their super 6 bout. the damage forced him too withdraw from the tournament. and essentially take a hiatus from the sport.

he returned to fighting 1 year and 9 months later against darryl cunningham, a journeyman who was fighting guys with losing records and whose biggest fight was a win against antwun echols. (echols was beyond washed up having had lost 8 and drawn 3 times with only 1 win in his previous 12 fights)

my guess is that he's lost the taste for the fight game after being brutally KO'd by abraham. if you saw the fight you know direll was fucked up after the fight, he had no idea what happened to him and was crying and deeply traumatized. paired with the neurological damage he suffered, it may have helped him to realize there are more important things to him than the sport of boxing.