That's why he need to work hard for this fight since if he lost for sure we will not see the fight of Inoue - Casimero since for sure the camp of Inoue will belittle him for losing his past fight, But we know how strong Casimero is and for sure we can see a great fight to him so let see on how he can handle Butler since this fighter is quite good but I think Casimero has more advantage to defeat this guy.
Casimero has everything to lose and really nothing to gain from this fight if he losses this fight, all his chances to get Inoue and Donaire to fight him will go out in the window and he will have to start all over again, I have seen a lot of upsets in the past months the recent one is Mikey's loss to Martin, and this is one fight that I don't want upset to happen, I still believe the Casimero - Inoue fight has the making of a great fight.
Plus we can add that he have pay cuts towards this fight that's why its somehow unfair to him that this obligatory fight happened, that's why in other hand he really need to push his self to win since he has everything to lose once he belittle his opponent.
I also believe in Casimero he's still a lot to offer to us and I do hope that he win this fight since I want to watch him fight agains Donaire or even Inoue.
This upcoming mandatory fight is really a determinant factor for him what will come next to his career. Because if he wins, either he will fight with Inoue or Donaire. But if he will lose, the interest of fighting with Inoue may not come up again. As Inoue may want a different opponent that will give good ticket sales. So Casimero should really prepare for this fight because it is somewhat a reference to his next happenings of his boxing career.