There is only one concern for the Senators if they wait to sign defenceman Erik Karlsson: Somebody will make him an offer he can't refuse. While Senators GM Bryan Murray won't sit down with Karlsson's Toronto-based agent Craig Oster until later this month to have formal talks, the best-case scenario for the franchise would see a deal done before July 1. Though Karlsson, 21, is a restricted free agent, a couple of high-profile agents noted Tuesday he is the kind of player who could be targeted for an offer sheet. That could force the Senators to break the bank.