NHL Highlights: 21 Matchups That Will Shape the NHL Playoffs

It started six months ago. And after a grueling, arduous season of regular season hockey, several playoff hopefuls are running out of time.

Save for Washington, Chicago, Los Angeles and Colorado, every other NHL team's schedule is reduced to a mere three games, with razor-thin seeding margins still in play.

Some are fighting to make the playoffs, while others already locked into the second season seek more advantageous seeding opportunities.

Here is a night-by-night list of the most critical matchups any NHL fan should be glued to this week.

(all times Eastern)

Tuesday, April 3

• Toronto Maple Leafs at Buffalo Sabres: 7 p.m., HSBC Arena
• New York Rangers at Philadelphia Flyers: 7 p.m., Wells Fargo Center
• Pittsburgh Penguins at Boston Bruins: 7:30 p.m., TD Bank North Garden
• San Jose Sharks at Dallas Stars: 8:30 p.m., American Airlines Center
• Columbus Blue Jackets at Phoenix Coyotes: 10 p.m., Jobing.com Arena

Wednesday, April 4

• Detroit Red Wings at St. Louis Blues: 7:30 p.m., Scottrade Center

Thursday, April 5

• Buffalo Sabres at Philadelphia Flyers: 7 p.m., Wells Fargo Center
• New York Rangers at Pittsburgh Penguins: 7 p.m., Consol Energy Center
• Florida Panthers at Washington Capitals: 7 p.m., Verizon Center
• New Jersey Devils at Detroit Red Wings: 7:30 p.m., Joe Louis Arena
• Dallas Stars at Nashville Predators: 8 p.m., Bridgestone Arena
• Columbus Blue Jackets at Colorado Avalanche: 9 p.m., Pepsi Center
• San Jose Sharks at Los Angeles Kings: 10:30 p.m., Staples Center

Friday, April 6

• Phoenix Coyotes at St. Louis Blues: 7:30 p.m., Scottrade Center

Saturday, April 7

• Buffalo Sabres at Boston Bruins: 4 p.m., TD Bank North Garden
• Philadelphia Flyers at Pittsburgh Penguins: 4 p.m., Consol Energy Center
• Washington Capitals at New York Rangers: 6:30 p.m., Madison Square Garden
• Phoenix Coyotes at Minnesota Wild: 8 p.m., XCel Energy Center
• St. Louis Blues at Dallas Stars: 8 p.m., American Airlines Center
• Nashville Predators at Colorado Avalanche: 9 p.m., Pepsi Center
• Los Angeles Kings at San Jose Sharks: 10:30 p.m., HP Pavilion

Ryan O'Leary is a writer and researcher for Bleacher Report's Video Production Department with seven years experience in the sports industry.