He'll be fine and you'll be fine. Just wait when things get serious. He'll be your best player. If he can carry a budget team to the conference finals, he can certainly boost a competitive team to perform. He may have lost speed, but he still knows how to play hockey. When he's up and running, he dominates the ice as the norm. When teammates know where to be for them to help eachother, things will become much easier for the team. They need to be quicker on their feet, especially the wingers on the breakout. So many times they're too slow, because they don't expect Karlsson to solve his problems that fast.
That's why he dominated in Ottawa, his teammates assumed he would solve the situation very fast and acted upon it. They just blasted up the ice when he stole the puck and waited for gifts. Karlsson is an oddman rush expert, the best at breakouts and ridiculous at controlled entries, while being pretty much great at the rest, except wrestling.
That's the difference between Karlsson and Burns. Burns dominates the offensive zone and is good at getting there, while Karlsson just squeezes the whole ice.