The Maple Leafs will be without defenceman Jonas Frogren for up to six weeks after an MRI revealed two muscle tears in his arm, according to the Toronto Sun.
Frogren's injury occurred during the first period of Toronto's 5-4 loss to the Blackhawks on Saturday night.
"We thought it could be serious, but we really didn't know," Leafs GM Cliff Fletcher told the Sun. "It happened to Jonas on his first shift of the game but he kept playing (before leaving early in the second period)."
The absence of the 28-year-old Swede will put more stress on a Toronto defensive corps that saw Carlo Colaiacovo go to the St. Louis Blues as part of a trade for Lee Stempniak on Monday. In addition, Mike Van Ryn is not expected to be back in the Leafs' lineup until December as he nurses a broken left hand suffered back on Nov. 8.
The ailing Leafs squad had nine defencemen at one point this season but are now down to six. Ian White will be shifted to the blue line to fill in after spending nine games as a forward.