When Matthew Tkachuk was traded across the continent from the Calgary Flames to the Florida Panthers last July, he was trading teams, conferences and ways of life. It’s hard to imagine two places much more different than Western Canada and South Beach. Tkachuk thought that the Panthers, who have rolled into the playoffs with regularity in recent years, would do so again, but now he is in a fight as the Panthers are one point out of the last wild-card slot in the Eastern Conference with six games remaining.