NHL's 2017 outdoor games

Matt Cullen (7) of the Pittsburgh Penguins celebrates after scoring a goal during the third period of the game against the Philadelphia Flyers at Heinz Field.

Philadelphia Flyers goalie Michal Neuvirth (30) stops a shot by Pittsburgh Penguins' Sidney Crosby (87) with Brandon Manning (23) defending during the third period of an NHL Stadium Series hockey game at Heinz Field in Pittsburgh.

Nick Bonino (13) of the Pittsburgh Penguins is congratulated by his teammates after scoring a goal against the Philadelphia Flyers at Heinz Field.

Matt Murray of the Pittsburgh Penguins makes a save as Wayne Simmonds of the Philadelphia Flyers applies a screen during the third period of the game at Heinz Field in Pittsburgh. Pittsburgh defeated Philadelphia, 4-2.

A live penguin from the Pittsburgh Zoo on the ice before the Pittsburgh Penguins host the Philadelphia Flyers during a Stadium Series hockey game at Heinz Field.

Workers spray the ice prior to the Pittsburgh Penguins hosting the Philadelphia Flyers in a Stadium Series hockey game at Heinz Field.

Chicago Blackhawks center Artem Anisimov (15) shoots wide of St. Louis Blues goalie Jake Allen (34) during the third period in the 2016 Winter Classic.

Chicago Blackhawks defenseman Niklas Hjalmarsson (4) battles for the puck with St. Louis Blues defenseman Kevin Shattenkirk (22) during the second period in the 2016 Winter Classic.

Chicago Blackhawks goalie Corey Crawford (50) makes a save on a shot by St. Louis Blues right wing Vladimir Tarasenko (91) during the second period in the 2016 Winter Classic.

St. Louis Blues left wing David Perron (57) battles for the puck with Chicago Blackhawks defenseman Michal Kempny (6) during the second period in the 2016 Winter Classic.

Chicago Blackhawks defenseman Duncan Keith (2) battles for the puck with St. Louis Blues center Paul Stastny (26) during the second period in the 2016 Winter Classic.

St. Louis Blues right wing Vladimir Tarasenko (91) celebrates after scoring a goal against the Chicago Blackhawks during the third period in the 2016 Winter Classic.

Chicago Blackhawks defenseman Michal Kempny (6) is congratulated by teammates after scoring in the first period.

St. Louis Blues goalie Jake Allen (34) and defenseman Jay Bouwmeester (19) defend the net.

St. Louis Blues center Kyle Brodziak (28) battles for the puck between Chicago Blackhawks center Dennis Rasmussen (70) and center Tanner Kero (67).

St. Louis Blues defenseman Joel Edmundson (6) chases the puck in the corner.

A general view during the playing of the national anthem before the 2017 Winter Classic at Busch Stadium.

A general view of the Stan Musial statue at Busch Stadium before the Winter Classic.

Maple Leafs center Auston Matthews (34) is congratulated by fans as he walks off the field after scoring the game-winning goal in overtime against the Red Wings during the Centennial Classic.

Maple Leafs players embrace forward Auston Matthews (34) after he scored the overtime winner against the Red Wings in the Centennial Classic.

Maple Leafs center Auston Matthews (34) is congratulated by teammates after scoring the game-winning goal in overtime against the Red Wings during the Centennial Classic.

Maple Leafs forward Auston Matthews (34) scores the winning goal in overtime against the Red Wings during the Centennial Classic.

Toronto Maple Leafs center Tyler Bozak (42) fends off Detroit Red Wings defenseman Brendan Smith (2) as they go after the puck during the Centennial Classic ice hockey game at BMO Field. Mandatory Credit: Tom Szczerbowski-USA TODAY Sports

Toronto Maple Leafs defenseman Nikita Zaitsev (22) hits Detroit Red Wings left wing Thomas Vanek (62) during the Centennial Classic ice hockey game at BMO Field. Mandatory Credit: Tom Szczerbowski-USA TODAY Sports

Detroit Red Wings defenceman Brendan Smith (2) body checks Toronto Maple Leafs forward Leo Komarov (47) during the Centennial Classic ice hockey game at BMO Field. Mandatory Credit: Dan Hamilton-USA TODAY Sports

Toronto Maple Leafs fans Tammy McLean and Martin Hervieux take in the view from the back of the temporary south end seats during the Centennial Classic ice hockey game at BMO Field. Mandatory Credit: Dan Hamilton-USA TODAY Sports

Toronto Maple Leafs center Leo Komarov (47) goes after the puck against Detroit Red Wings defenseman Danny DeKeyser (65) during the Centennial Classic ice hockey game at BMO Field. Mandatory Credit: Tom Szczerbowski-USA TODAY Sports

Detroit Red Wings fan sports head gear to support his team.

Brian Adams performs during the first intermission at the Centennial Classic.

Red Wings forward Kris Draper (33) attacks with the puck against the Maple Leafs during the Centennial Classic Alumni Game.

Maple Leafs goalie Mike Palmateer (29) saves a penalty shot attempt by Red Wings forward Tomas Holmstrom (96) during the Centennial Classic Alumni Game.

Maple Leafs forward Lanny McDonald (7) gets ready for before the start of the Centennial Classic Alumni Game.

Maple Leafs defenseman Dave Ellett (4) knocks the puck off the stick of the Red Wings' Jiri Fischer (2) during the Centennial Classic Alumni Game.

Red Wings forward Brendan Shanahan (14) shares a hug with Maple Leafs forward Tie Domi (28) after the Centennial Classic Alumni Game.

Maple Leafs goalie Curtis Joseph (31) stops a wrap-around attempt by Red Wings forward Kris Draper (33) during the Centennial Classic Alumni Game.

Maple Leafs right wing Nikita Soshnikov (26) skates with the puck during practice for the Centennial Classic.

A general view of BMO Field as the Red Wings practice two days before playing against the Maple Leafs in the Centennial Classic.

Red Wings center Dylan Larkin (71) practices for the Centennial Classic.

Maple Leafs head coach Mike Babcock talks to centers Mitch Marner (16) and Tyler Bozak (42) and left wing James van Riemsdyk (25) as defenseman Jake Gardiner (51) looks on during practice for the Centennial Classic.

Maple Leafs center Leo Komarov (47) smiles during practice for the Centennial Classic.

Former St. Louis Blues goalie Martin Brodeur, right, looks on as former Chicago Blackhawks' Kyle Calder, Reggie Kerr, second from left, and Jim Cummins celebrate after scoring a goal during the winter classic alumni outdoor game at Busch Stadium on Dec. 31, 2016.

Members of the St. Louis Blues alumni celebrate after scoring a goal against the Chicago Blackhawks during the 2017 NHL Winter Classic alumni game at Busch Stadium.

Former St. Louis Blues forward Brett Hull, left, battles along the board with former Chicago Blackhawks forward Grant Mulvey during the winter classic alumni outdoor game at Busch Stadium.

Former St. Louis Blues forward Wayne Gretzky participated in the alumni game at Busch Stadium.

Former St. Louis Blues goalie Martin Brodeur stays low.