What doesn't make sense, if Khan really wanted to fight Pacquiao or Mayweather then why not fight Brook?

Not only would Brook bring him a huge payday but it would be the last available belt. This is a nice bargaining chip. If someone has one unifying is nice but being undisputed is so rare anymore. Having that opportunity to offer that prize has value.

It makes perfect sense for Khan. Why won't he take a shot??