It takes a lot to get Aleksander Barkov to curse and Matthew Tkachuk, on the eve of his first training camp with the Florida Panthers, nearly got his captain there Wednesday — sort of. After wrapping up some precamp testing at the Florida Panthers IceDen, Barkov recalled the first text conversation he had with his new All-Star teammate after the Panthers’ blockbuster July trade brought him to South Florida. “The first message,” Barkov said, with his usual sheepish smile, “is, Effing right.” A little while later, Tkachuk laughed at the exchange. For Barkov, it was out of place — even if he didn…