Breaking down Mitch Marner's demotion, Leafs' pursuit of a blueliner after GM Treliving's presser

Toronto Maple Leafs general manager Brad Treliving met with reporters after Monday’s practice to address several topics, including the pursuit of a new defenseman following John Klingberg’s move to long-term injured reserve with a hip injury.

The biggest news was an in-house lineup shuffle: Mitch Marner was dropped down to the second unit, joining John Tavares and Tyler Bertuzzi, while William Nylander was promoted to the first line with Auston Matthews and Matthew Knies. In essence, this ought to provide Toronto with a turbo-charged top line as Nylander has been playing like a Hart Trophy contender through the first quarter of the season while Matthews remains among the NHL’s premier goal-scorers.

This change was a direct response to Marner’s middling play over the weekend. Maple Leafs head coach Sheldon Keefe offered a candid critique of Marner’s game prior to Saturday’s 3-2 loss to the Pittsburgh Penguins.

“Just not executing at the level that you’d expect from Mitch,” Keefe said of Marner's recent performance on Saturday afternoon via The Athletic’s Jonas Siegel. “Mitch hasn’t found his groove yet.”

Marner offered a poor response Saturday. He was caught way too far up the ice on Jake Guentzel’s goal, which tied the game 28 seconds after the Maple Leafs opened the scoring. He lost the puck during a power play which almost led to a Penguins short-handed goal.

Marner’s defensive impact has also waned. Although he was a Selke finalist last year, the 26-year-old currently ranks 272nd out of 431 eligible players (200 minutes or greater played at 5-on-5) in expected goals against per 60 via Natural Stat Trick.

Matthews, for what it’s worth, ranks 268th, although his 17 takeaways versus nine giveaways at 5-on-5 has been a plus on the defensive side.

“It's just been great reluctance on my part to make a change to the (John) Tavares group in particular, and with Willy in particular,” Keefe said of the changes Monday. “[Nylander has] found a nice groove, his game has been going so well that we were reluctant to make a change to him and his situation.”

In light of the move today, let's look at what has and hasn't worked with the Matthews-Marner combination, and why the lineup shuffle may be the best thing for all parties involved.

Performance of the first line and "core four"

Tyler Bertuzzi was initially placed on the Matthews-Marner line to start the season. Matthews went ballistic during the opening week with consecutive hat tricks and Marner registered three assists in two games, but Bertuzzi struggled to generate any real chemistry with Toronto's top line.

Bertuzzi caught fire alongside Tavares and Nylander and that line is Toronto’s most commonly-used unit, with a plus-4 goal differential while hovering just below a 60% share of the expected goals.

Matthews and Marner have been paired together in three of Toronto’s most commonly used groups at 5-on-5. Here’s how it’s worked out so far:

These aren’t particularly bad results in a vacuum for Toronto’s second-, third- and fifth-most used forward combos — but hockey isn’t played in a vacuum. If Matthews and Marner are essentially playing to a draw when paired with Knies, there’s a desperate need for change.

Nylander-Matthews and Tavares-Marner have been used together before throughout their shared tenures, so it’s not an unfamiliar concept for Keefe to deploy and it’s not too late to start experimenting again, with a cabal of new linemates surrounding the core four.

Here’s how these duos fared in 2022-23:

Bertuzzi isn’t the exact same player as Michael Bunting, but he replicates many similar qualities so we’re tossing nuance aside for a second and using Bertuzzi as the Bunting stand-in this season. Matthews and Nylander have built some incredible chemistry together over the years. Both players are excellent at creating chances independent of their linemates in large part due to their terrific releases which they can get off nearly anywhere inside the offensive third.

Tavares’ improved skating and overall cerebral qualities bode well with Marner’s all-world playmaking. They need just a glance at each other to get open and unlock the optimized versions of each other’s games. This could work. And there’s enough data to support that this may be the idealized version of Toronto’s forward corps.

It is worth noting that Nylander has taken another step this year, becoming a more willing and complete shooter. He’s winning puck battles aggressively and he’s shown terrific defensive attention to detail that has often led to instant offense — which hasn’t always been true in the past.

What has worked with the Matthews-Marner-Knies combination

OK, so the sky isn’t falling for Matthews and Marner, both of whom have shown individual flashes of brilliance. Matthews started the year on fire, while Marner registered back-to-back four-point performances during the first week of November against the Sabres and Lightning, respectively.

Marner leads the Maple Leafs with 13 points at 5-on-5, while Matthews ranks second with 12. In a vacuum, again, this would be fine, but we’re talking about two extraordinary players, one of whom is a former MVP, the other one coming off a tour-de-force 99-point season imbued with all-around excellence.

Although the production hasn’t been there lately, Meghan Chayka of Stathletes researched that Marner-Matthews are among the league’s elite one-two combinations.

Yahoo Sports Canada's Nick Ashbourne highlighted Marner’s long-range passing and it’s still true that No. 16 is seeking instant offense through stretch passes. It’s been a catch-22 of sorts for Marner: he’s been at his best when seeking instant offense through long-range bombs as displayed below, or lateral passes off the rush to a cutting Matthews or Knies.

Unfortunately, this same quality has worked against Marner as well: he’s often looking for the spectacular play or an audacious cut through several defenders, when a simple pass to extend possession would do just fine.

This pass from Marner to Matthew Knies against the Wild on Nov. 19 — Marner’s last game with a point — is a defining example of what Marner has done well this year.

Knies scores in the below clip during a Nov. 6 game against the Lightning and it’s the result of a concerted three-man effort where Knies and Matthews win a puck battle together, Matthews gets the puck back to Marner, who throws it at the net and Matthews cleans it up.

Good things happen when you simplify the game and Marner’s been at his best when he does the small things well.

Marner and Matthews still thrive with their two-man game in small spaces, particularly when Marner is on the half-wall and Matthews can use his frame to either cut to the slot, or work behind the net to extend possessions.

What hasn’t worked with the Matthews-Marner combination

Matthews and Marner aren’t getting the best out of each other anymore — which could change in an instant given their chemistry, pedigree and continuity and off-ice brotherhood — but the fault primarily lies with Marner, who sports a minus-1 goal differential at 5-on-5, while Matthews is merely a plus-1 despite being firmly in the Rocket Richard race.

And not to put too fine a point on this part, but Knies’ best results have often come as a result of his two-man game with Calle Jarnkrok, along with a third-period flash of brilliance with Max Domi during a 4-3 win against the Lightning on Oct. 21.

It’s also worth noting that Marner has been a staple of the team’s top penalty kill and the Maple Leafs rank 18th with a 77.8% success rate. Of course, this is a group project of sorts attached to Marner, David Kampf and several rotating defensemen but it’s been a sharp decline from the former's Selke-caliber season a year ago. There was an initial idea that placing the Maple Leafs’ best forwards on the penalty kill would be an avenue for surplus minutes and after initially strong returns, this idea largely hasn’t worked.

We’ve already discussed how Marner is often looking for the audacious play rather than the simple one. There’s been a razor-thin margin of error but Marner hasn’t found Matthews in optimal shooting lanes after the first week of November and it’s time for an adjustment. We’re only a quarter of the way through the season and Keefe should tinker with his lines until the Maple Leafs strike gold.

Treliving seeking out a trade for defensemen

In non-Matthews and Marner news, Treliving revealed that he will be pursuing another defensemen in light of John Klingberg’s hip injury. Klingberg and his $4.15 million salary have been placed into the team’s long-term injured reserve pool.

“It's certainly an area we'd like to help ourselves,” Treliving said on Monday. “When you're sitting here in November, that's easier said than done. But that's certainly an area that we look at and see if there's a way that we can help ourselves.”

Toronto currently has $4.65 million in cap space via CapFriendly and can add three more professional contracts to its current pool. Flames defenseman Nikita Zadorov has been floated as a potential trade target, given his past relationship with Treliving. Zadorov landed a huge-open ice hit on Tyler Bertuzzi on Nov. 10, then Zadorov’s agent, Dan Milstein, fueled rumours that his client wanted out of Calgary.

Another Flames defenseman, Chris Tanev, has also been linked to the Leafs as a potential target. Tanev grew up in Toronto and was a prototypical late bloomer but his strong relationship with then-Canucks executive Dave Gagner provided him with a chance at the NHL and he’s been one of the league’s best shot blockers for the past decade.

(Editor's note: All stats current entering Monday’s games)