Here is Leafs actual situation (post Kapanen trade) under contract for next year.
Total Cap committed 2020-21 = $73,708,533 (16 players)
Total Cap upper limit 2020-21 = $81,500,000
Free Cap Space Available = $7,791,467 ( for 7 players to 23 man roster)
Breakdown
Forwards
Matthews, Auston ........ $11,634,000
Tavares, John .................. $11,000,000
Marner, Mitchell ............ $10,893,000
Nylander, William .........$6,962,366
Kerfoot, Alexander .......$3,500,000
Johnsson, Andreas ......$3,400,000
Hyman, Zach ..................$2,250,000
Engvall, Pierre ................$1,250,000
Total 8 forwards & $50,889,366 cap
Defense
Rielly, Morgan .............. $5,000,000
Muzzin, Jake ..................$5,625,000
Holl, Justin ......................$2,000,000
Sandin, Rasmus ..........$894,167
Rosén, Calle ...................$750,000
Marincin, Martin ..........$700,000
Total 6 Dmen & $14,969,167 cap
Goalies
Andersen, Frederik ........$5,000,000
Campbell, Jack ................$1,650,000
Total 2 Goalies & $6,650,000 cap
+
Retained Salary
Kessel, Phil ......................$1,200,000
All pending RFAs or UFAs from last season are not included unless re-signed.