According to the elder Tkachuk brother's former teammate Adam Ruzicka - he believes things had become sour between Tkachuk and the Flames.
Ruzicka stated in an interview that Tkachuk wanted to be the captain, but the Flames wouldn't accomodate on that front, which ultimately led to the offseason trade between Flames and Panthers.
I don't know what else played a role there but he really insisted on becoming a captain and think they couldn't fulfill that request which played a big role in him leaving
Did the Panthers cash-in on a ridiculous decision by the Flames? Or did the Flames get better with the Acquisitions of Mackenzie Weegar and Jonathan Huberdeau?