They still struggle defensively, giving up the seventh most shots per game in the league, and one thing that is just as concerning is their penalty kill. It currently ranks 16th and is killing off 80.3 percent of their penalties. At this point, they are almost certainly playing the Bruins again in the playoffs, and Boston has the second-best power play in the league (26.8%).
The good news is the Leafs have taken the fewest minor penalties in the league, and that is why, in the big picture, they have given up the fifth fewest power-play goals despite not owning an elite penalty kill.