During the 1981–82 season, Ballard considered Imlach's health to be too poor for him to continue as general manager. But even with Imlach gone, Sittler's relationship with the Leafs worsened to the point where he told Ballard and acting general manager Gerry McNamara at the end of November he would waive his no-trade clause if he was sent to the Flyers or the Minnesota North Stars. In the first week of December, Eagleson agreed to terms with Flyers' owner Ed Snider and North Stars' general manager Lou Nanne. But it took another seven weeks for the Leafs to make a deal. During that time, Sittler added the Islanders and Buffalo Sabres to the list of teams he could be traded to. On January 5, 1982, on advice from his physician, Sittler walked out on the Leafs, saying he was "mentally depressed" because a trade was taking so long to complete.
Finally, on January 20, 1982, the 31-year-old Sittler was traded to the Flyers for Rich Costello plus the Hartford Whalers' second-round pick in the 1982 draft (used by the Leafs to select Peter Ihnačák), and future considerations, which ended up being Ken Strong. Only Ihnacak would play regularly for the Leafs. In 1980, Imlach had rejected an offer from Philadelphia, who were said to be willing to trade Rick MacLeish and André Dupont for Sittler.