If you thought it was weird to see a football game postponed by a blizzard, what do you think about a hockey game postponed by rain?

The Pittsburgh Penguins are scheduled to host the Washington Capitals in the National Hockey League’s fourth annual outdoor Winter Classic, but the Saturday, January 1 game at Heinz Field is in some danger of being pushed back because of rain. As much as half an inch of rain is expected to fall Saturday.

The unseasonable warmth — weather.com currently projects a high temperature of 49 degrees Saturday, 13 degrees higher than the usual January 1 peak — is not an issue. According to the Sporting News, Heinz Field will be equipped with a “sophisticated refrigeration system” that will ensure the ice remains at 22 degrees. However, there’s nothing to prepare the ice for withstanding heavy rains, which would turn the surface slushy and uneven and obviously increase the risk of injury.

The Washington Post reported this week that the NHL can delay the start of the game — which will be televised on NBC — until 8 pm, seven hours after its scheduled faceoff. Should the conditions remain unplayable, the game could be postponed until Sunday at noon. If it can’t be played by then, the game would be rescheduled for later in the season — indoors at the Penguins’ Consol Energy Center.

Whenever the game is played, it will take place in front of a sellout crowd. All 67,000 seats at Heinz Field were sold long ago. As of this afternoon, Thursday, December 30, StubHub.com had just 236 tickets to the Winter Classic, the cheapest of which was listed at $273 for a seat in Upper End 519, well above the playing surface. That ticket is $23 more expensive than the face value of the priciest seat offered when tickets first went on sale.

The Winter Classic is perhaps the most anticipated event on the NHL’s regular season schedule. This year’s game pits two of the league’s marquee franchises and its two best players, the Penguins’ Sidney Crosby and the Capitals’ Alex Ovechkin. It is also a rematch of the classic 2009 Eastern Conference semifinals in which the Penguins came back from a two-games-to-none deficit to knock off the Capitals in seven games on their way to winning their first Stanley Cup since 1992.

In addition, all the commercial time on the NBC broadcast has been sold out and the game is expected to generate 20 percent more revenue this year than last year, when the Boston Bruins and Philadelphia Flyers played on New Year’s Day at Fenway Park.