The Finns reduced the number of players from 28 to 23, which is the maximum roster size at the 2017 IIHF World Junior Championship. Defencemen Otto Leskinen, Jarkko Parikka and Robin Salo as well as forward Aaro Vidgren won’t be with the team anymore. Also forward Jouka Juhola was cut but will continue practising with the team as a backup in case of injury.

Also Russia named its 23 players it plans to register for the World Juniors. Five players had to leave the team including defencemen Kamil Fazylzyanov and Artyom Chmykhov as well as forwards Nikita Li, Nikita Korostelyov and Artur Tyanulin.

Also Slovakia named its 23-man roster while Denmark trimmed its roster after a 3-2 exhibition-game win against Latvia and has now 24 players on the current roster. Defenceman Jakob Jessen and forward Kristoffer Sogaard will have to travel home.

Finland's roster as of 23 December

Goaltenders:
Karolus Kaarlehto, TPS Turku
Markus Ruusu, JYP Jyvaskyla
Veini Vehvilainen, JYP Jyvaskyla

Defencemen:
Miro Heiskanen, IFK Helsinki
Olli Juolevi, London Knights (OHL)
Jesper Mattila, Boston College (NCAA)
Juho Rautanen, Jokerit Helsinki
Vili Saarijarvi, Mississauga Steelheads (OHL)
Urho Vaakanainen, JYP Jyvaskyla
Juuso Valimaki, Tri-City Americans (WHL)

Forwards:
Kasper Bjorkqvist, Providence College (NCAA)
Henrik Borgstrom, Denver University (NCAA)
Otto Koivula, Ilves Tampere
Janne Kuokkanen, London Knights (OHL)
Joona Luoto, Tappara Tampere
Julius Mattila, Boston College (NCAA)
Julius Nattinen, Windsor Spitfires (OHL)
Petrus Palmu, Owen Sound Attack (OHL)
Arttu Ruotsalainen, Assat Pori
Aapeli Rasanen, Sioux City Musketeers (USHL)
Eeli Tolvanen, Sioux City Musketeers (USHL)
Kristian Vesalainen, HPK Hameenlinna
Teemu Vayrynen, TPS Turku

Head Coach:
Jukka Rautakorpi

Russia's roster as of 23 December

Goaltenders:
Anton Krasotkin, Loko Yaroslavl
Ilya Samsonov, Metallurg Magnitigorsk
Vladislav Sukhachyov, Chelmet Chelyabinsk

Defencemen:
Grigori Dronov, Metallurg Magnitigorsk
Vadim Kudako, Severstal Cherepovets
Yegor Rykov, SKA St. Petersburg
Mikhail Sergachyov, Windsor Spitfires (OHL)
Mikhail Sidorov, Ak Bars Kazan
Artyom Volkov, Dynamo Balashikha
Yegor Voronkov, Vityaz Podolsk
Sergei Zborovski, Regina Pats (WHL)

Forwards:
Denis Alexeyev, HK Ryazan
Kirill Belyayev, Yugra Khanty-Mansisk
Denis Guryanov, Texas Stars (AHL)
Kirill Kaprizov, Salavat Yulayev Ufa
Pavel Karnaukhov, CSKA Moscow
Danila Kvartalnov, CSKA Moscow
Alexander Polunin, Lokomotiv Yaroslavl
German Rubtsov, Vityaz Chekhov
Yakov Trenin, Gatineau Olympiques (QMJHL)
Kirill Urakov, Torpedo Nizhni Novgorod
Mikhail Vorobyov, Salavat Yulayev Ufa
Danil Yurtaikin, HK Ryazan

Head Coach:
Valeri Bragin

Slovakia's roster as of 23 december

Goaltenders:
Roman Durny, MHk 32 Liptovsky Mikulas
Adam Huska, University of Connecticut (NCAA)
Matej Tomek, Unviersity of North Dakota (NCAA)

Defencemen:
Martin Bodak, Tappara Tampere (FIN)
Erik Cernak, Erie Otters (OHL)
Martin Fehervary, Malmo Redhawks (SWE)
Mario Grman, HC Topolcany
Samuel Hain, HC Topolcany
Andrej Hatala, Dukla Trencin
Oliver Kosecky, HC ´05 Banska Bystrica
Michal Roman, Ocelari Trinec (CZE)

Forwards:
Martin Andrisik, HC ´05 Banska Bystrica
Radovan Bondra, Vancouver Giants (WHL)
Marek Hecl, Dukla Trencin
Filip Lestan, HV71 Jonkoping (SWE)
Patrik Osko, MHk 32 Liptovsky Mikulas
Oliver Pataky, Dukla Trencin
Milos Roman, Ocelari Trinec (CZE)
Adam Ruzicka, Sarnia Sting (OHL)
Boris Sadecky, Dukla Trencin
Marek Sloboda, HK VSR SR 20
Miroslav Struska, MHk 32 Liptovsky Mikulas
Marian Studenic, Hamilton Bulldogs (OHL)

Head Coach:
Ernest Bokros

Denmark roster as of 23 December

Goaltenders:
Emil Gransoe, Topeka Roadrunners (NAHL)
Kasper Krog, SonderjyskE Vojens
Lasse M. Petersen, Red Deer Rebels (WHL)

Defencemen:
Oliver Gatz Nielsen, Herning Blue Fox
Morten Jensen, Rogle Angelholm (SWE)
Anders Koch, Esbjerg Energy
Oliver Larsen, Odense Bulldogs
Christian Mieritz, Leksands IF (SWE)
Mathias Rondbjerg, Rungsted
Nicolai Weichel, Rungsted

Forwards:
Niklas Andersen, Esbjerg Energy
Rasmus T. Andersson, HV71 Jonkoping (SWE)
Joachim Blichfeld, Portland Winterhawks (WHL)
William Boysen, Rungsted
Nikolaj Christensen-Krag, Rogle Angelholm (SWE)
Mathias From, Rogle Angelholm (SWE)
Frederik Hoeg, Odense Bulldogs
Jeppe Jul Korsgaard, Aalborg Pirates
Tobias Ladehoff, Aalborg Pirates
David Madsen, Vaxjo Lakers (SWE)
Daniel Nielsen, Herning Blue Fox
Jonas Rondbjerg, Vaxjo Lakers (SWE)
Alexander True, Seattle Thunderbirds (WHL)
Christian Wejse, Blainville-Boisbriand Armada (QMJHL)

Head Coach:
Olaf Eller