The Leafs defense is slightly improved
Chris Tanev was the Leafs biggest free-agent acquisition. Signing the 34-year-old to a six-year term is questionable, but Treliving desperately wanted his skillset added to the blue line.
The Maple Leafs also added Oliver Ekman-Larsson and Jani Hakanpaa to their defense. Both are veterans that come with risk and low expectations.
Ekman-Larsson was solid in the Mark Giordano role with the Stanley Cup champion Florida Panthers, but his career looked to be derailing before that. Toronto gave him a crazy four-year deal and he will be asked to do more with the Leafs than he did with the Panthers, which is likely a mistake. Whether he can handle the added responsibility will be an important key for the Leafs defense.
Hakanpaa comes with significant injury concerns surrounding his knee. If he can eventually join the lineup, his size and reach should help the team's atrocious penalty killing, but hurt them at even-strength where he won't be anywhere close to effective.
Adding Tanev makes the Leafs better. Not playing Liljegren makes them worse. It's hard to know what to make of the Leafs blue-line. It's very, very old and very average. It might be good, but their lack of a high-end option will hurt them more than anything else.
The biggest concern is this is an aging group. The Leafs top defensemen are all 30 or older. Injuries are likely to be an issue. A decline in play is sure to happen for some of these players within a couple of years. The team's defense is better, but it doesn't measure up to most other title contenders.