Chicago ? His starters threw four straight complete games to win the AL pennant, so it was no surprise and a no-brainer when White Sox manager Ozzie Guillen said Thursday he was sticking with the same rotation for the World Series.

“The reason is obvious,” Guillen said.

Jose Contreras will pitch Saturday night’s opener against the Houston Astros, his third straight Game 1 starting assignment in these playoffs.

This time, though, he’ll be going against Roger Clemens, his former teammate with the New York Yankees, a 300-plus-game winner and a no-doubt Hall of Famer on the first ballot.

Contreras and Clemens were teammates in 2003 when New York lost the World Series to Florida. Contreras relieved in four games against the Marlins, going 0-1 with a 5.68 earned-run average. Contreras said watching Clemens from the same side was a special learning experience.

“The way he pitched looked so perfect, you wanted to try to do the same,” Contreras said through a translator.

A veteran of numerous international competitions while he was the best pitcher in Cuba and with three playoff games already this season, Contreras said he didn’t expect jitters to be a problem.

“I’m not nervous, just happy to be on this stage,” he said.

After going 11-2 in the second half of the season and winning his final eight starts of the regular season, Contreras beat the Red Sox in the opener of the division series. He lost Game 1 of the AL championship series to the Angels and then defeated Los Angeles in the clincher last Sunday, pitching Chicago’s fourth straight complete game.

“Two good pitching staffs going at it. Hopefully it is a low-scoring game,” White Sox outfielder Jermaine Dye said.

“We’re going to be facing pretty good pitching. Some guys I faced in the past. Hopefully they don’t have their ‘A’ games and we do.”

Mark Buehrle, who has won both of his playoff starts, will be working on 10 days’ rest when he faces Andy Pettitte in Game 2.

Down in Houston, Jon Garland goes against NLCS MVP Roy Oswalt in Game 3 at Minute Maid Park. Freddy Garcia gets the Game 4 start against Brandon Backe.

“We can’t think, ‘Oh, we’re facing Roger Clemens.’ We’re facing the Houston Astros,” Buehrle said.

And like the White Sox, the Astros’ aces will be well rested.

“A lot of people talk about Clemens and Andy, but they have another one there who throws the ball better than them – Oswalt,” Guillen said. “They have a lot of experience. I think Andy is the best pitcher in the postseason in a long time.”