Erik Karlsson is back. The reigning Norris Trophy winning defenceman will make a stunningly-quick return from Achilles surgery against the Washington Capitals tonight. The Senators can clinch a playoff berth with a victory. Karlsson will be paired with Marc Methot in even-strength situations and will be a welcome addition to the struggilng powerplay. Karlsson hasn’t played since Feb. 13, when the infamous Matt Cooke incident occurred in Pittsburgh. Karlsson had surgery the following day in Ottawa. Thursday represents the 10-week mark since the surgery. The normal recovery time for a professional athlete from Achilles surgery is five to six months. Craig Anderson will start in goal for Senators. In many ways, it’s a meaningless game for the Capitals. They wrapped up the Southeast Division title — and the third seed in the Easten Conference playoffs — by defeating Winnipeg 5-3 on Tuesday. But statistics matter, too.