DENVER • A mild snowstorm and freezing temperatures Saturday put Rocktober on ice. So the Philadelphia Phillies subbed J.A. Happ for Pedro Martinez, while Colorado stuck with Jason Hammel for Game 3 of the NL division series tonight at Coors Field.

Major League Baseball postponed Saturday’s game about 10 a.m. with light snow falling in Denver as temperatures dipped to a record-low 17 degrees. The snow stopped before noon, but temperatures never climbed beyond the 20s, and if the game had been played, it would have topped an April 1997 game (28 degrees) as the coldest in Rockies history.

National Weather Service forecasters today call for freezing fog and a 10 percent chance of snow before noon, with a high near 49 degrees, a low around 31 and winds between 4 and 8 mph, creating a chilly first pitch at 8:07 p.m. The high for Game 4 on Monday (the time will be determined based on today’s results in the ALDS) is 45, and the low is 32.

An extra day of rest means the Phillies will start a rookie left-hander in Happ in a best-of-five series that’s tied 1-1 and save Martinez, whose surgically repaired pitching shoulder might not have responded well to poor conditions. Happ was knocked out of Game 2 when the only batter he faced, Seth Smith, sent a line drive off his left leg in the seventh inning.

Plus, shuffling the rotation makes Game 1 starter Cliff Lee ready for Game 4 on full rest and Game 2 starter Cole Hamels ready for a possible Game 5 on Tuesday in Philadelphia, also on full rest. A three-time Cy Young Award winner, Martinez likely will pitch out of the bullpen sometime in Denver, and 12-game winner Joe Blanton is available in relief.

The Rockies like Hammel, a 10-game winner making his first postseason start, given his consistency down the stretch, and they’re happy now having Ubaldo Jimenez for Game 4 and Aaron Cook for a potential Game 5, both on normal rest. Their bullpen also won’t be tired, particularly Franklin Morales, who pitched in both games in Philadelphia.

When Happ last started against Colorado, in August, he threw a complete-game, four-hit shutout in Philadelphia. However, Happ said he doesn’t “really read too much into that. … I’m definitely going to try to take the same aggressiveness that I had that game and try to pitch the same way and stay within myself, and hopefully I’ll have success that way.”

Philadelphia manager Charlie Manuel said picking Happ was an easy decision since he’s a firm believer in “putting lefties against this team. We line up better that way, and that can put some of our best pitching on these guys. … When the game starts and the ball is in the pitcher’s hand, he controls the game, and I think good pitching beats good hitting.”

Rockies manager Jim Tracy feels comfortable in Hammel, who won his lone decision this season against the Phillies, also in August in Philadelphia.

“He has created a mindset in our clubhouse since the All-Star break, that when he goes out there to pitch,” Tracy said, “we can anticipate he’s going to pitch well, and he’s going to keep us in the game and give us a chance to win.”

Hammel called his start a “huge opportunity for me. … I’m not going to make too much of a big deal of this. It’s obviously an important game. They’re all important games.”

GOT TICKETS?

Tickets for Game 3 of the NL division series between the Rockies and Phillies, originally scheduled for Saturday at Coors Field, will be honored tonight. First pitch is 8:07 p.m.

Tickets for Game 4, originally scheduled for today at Coors, will be honored Monday. No time has been set. If the Yankees beat the Twins and the Angels beat the Red Sox today to complete sweeps, Monday’s game will start at 5 p.m. If either ALDS isn’t finished, the Rockies game will begin at 3 p.m. If both ALDS are ongoing, it will start at noon.

If necessary, Game 5 is 4:07 p.m. Tuesday in Philadelphia. The winner advances to face the Dodgers in the NL championship series beginning Thursday in Los Angeles.

Light snow covered Coors Field on Saturday, forcing Game 3 of the NL division series between the Rockies and the Phillies to be postponed. Photo by Associated Press