Kailer Yamamoto is still dressing on a couple of folding chairs in the middle of the Edmonton Oilers dressing room, and picking up the pucks after practice as rookies are expected to do. But as he celebrated his 19th birthday on Friday at Rogers Arena, skating on the Oilers second line with Milan Lucic and Ryan Nugent-Hopkins, his situation here has become the worst-kept secret in camp. Yamamoto will open the regular season with the Oilers against the Calgary Flames here on Wednesday. It’s just that no one wants to say it out loud quite yet. “If we had to make a decision right now, he would start the season (in the NHL),” Oilers general manager Peter Chiarelli told Sportsnet on Friday, while taping an interview to run closer to Opening Night. “We’ve still got some time left, but he’s certainly earned the spot he is in right now.” Yamamoto, who leads all NHLers with five pre-season goals, is going to Vancouver for the final exhibition game and playing right wing on a key line. He’ll get some second unit power play time, and begin what will amount to a second training camp when he plays his first NHL game Wednesday.