Colborne also has been given very sheltered minutes. I think he has his work cut for him come training camp. He's no good on the 4th line, so if he's not a better option than Reinhart, Granlund, Knight, Byron or Agostino in the top 9, I can't see him being a Flame very long. Consistency is his main issue right now.
He's better than all the guys you listed, so I'm sure he'll be back.