I don't think tank in required but it might end be the end result.
Leafs have made themselves very vulnerable this year due to lack of team depth both at forward and defense.
Last season anyone of Bolland, Kulemin and Raymond were capable of moving up into the top 6 as an injury replacement and on D players like Gleason and Ranger provided depth and experience. This year they will only have 6 Dmen signed with NHL experience and one of those is Rielly with just 1 year under his belt..
Injuries to players particularly those playing top 2 lines and top 4 D will really test Leafs depth through inexperience.
yeah, if any of Bernier Kessel or Phaneuf get injured for any substantial length of time, the team's postseason hopes are pretty much over with. then again, that was true last year and it isn't something one can fix in a single offseason.
Hopefully Kontiola and Santorelli are much better players than the kinds of guys like this the Leafs have gotten in the past such as Wallin, Khavanov, etc.