Hi, I see people are worried about the Leafs ability to stay under the cap. It won't be an issue this year but will be in 19-20 when Matthews and Marner's new salaries kick in.
I made an attempt to see if they can keep all 4 in 19-20 (Matthews/Marner/Nylander/Tavares).

First, the cap is about 80M this year, I predicted 82.5M in 19-20. As you can see, the Leafs can stay under the cap providing they do a couple of small moves. They would need to buy out Marleau after this coming year and they could only keep one of Gardiner or Hainsey on D, but they can do it. Here is what it would look like.
Forwards (14) Salary (Millions) in 19-20
Matthews $12.00 Estimate
Tavares $11.00
Marner $8.00 Estimate
Nylander $6.50 Estimate
Kadri $4.50
Hyman $2.25
Brown $2.10
Kapanen $1.75 Estimate
Johnsson $1.25 Estimate
Leivo $1.00 Estimate
Lindholm $0.93 Estimate
Gauthier $0.93 Estimate
Grundstrom/Aaltonen $0.93 Estimate
Mueller/Moore $0.93 Estimate
Total $ spent on forwards $54.05

Defence (7)
Reilly $5.00
Zaitsev $4.50
Gardiner or Hainsey $4.00 Estimate
Carrick $1.25 Estimate
Liljegren/Rosen $0.90
Dermott $0.88
Marincin/Holl/Borgman $0.80
Total $ spent on defencemen $17.33

Goalie (2)
Anderson $5.00
Sparks/Picard $0.80 Estimate
Total $ spent on defencemen $5.80

Other
Kessel $1.20
Marleau - cost to buyout of last year of contract $2.08

19-20 Cap Estimate $82.50
Total Cap Used $80.46
Cap Available $2.04 Under Cap
Am I far off? It just shows they can do it, buying out a 39 year old Marleau from the last year of his contract adds 4M space to the cap. The forward group here is very strong but as you can see, the defence is young.

Am I far off? Please feel free to comment.