Phil Kessel and lessons of LTIR

When Phil Kessel hit LTIR last season, it ended up affecting Toronto's cap flexibility. Getty Images

The Toronto Maple Leafs found out the hard way how long-term injuries can hurt teams in the salary-cap world. The Philadelphia Flyers and Boston Bruins are among those at risk of following in their footsteps.

The Maple Leafs, who needed to place players on long-term injured reserve (LTIR) to stay under the cap last season, are now paying for it in the form of a $1.4 million bonus overage penalty that is deducted from their spending limit.

That's because LTIR -- a complicated system that was actually designed to provide cap relief -- can cause major cap headaches for teams heavy in performance bonuses.