Fans will obsess over it. Participants won't admit it -- publicly, anyway. But Sunday's Yankees-Red Sox pitching matchup, conjured as if from a dream, is about more than baseball.

"With his age, and what he's done," said Yankees pitching coach Ron Guidry of Roger Clemens, "it's just another game."

But it is not. Clemens and Curt Schilling, larger-than-life nemeses on each side of baseball's ancient rivalry, have never faced each other as members of the Yankees and Red Sox.

The future Hall of Famers last squared off on Nov. 4, 2001, in the World Series. Clemens, the ace of the defending World Series champion Yankees, threw 6 1/3 innings in an epic Game 7, striking out 10 Arizona Diamondbacks before leaving New York in a 1-0 hole.

Schilling lasted 7 1/3 innings for Arizona, lifted after an Alfonso Soriano home run gave the Yankees a 2-1 lead in the eighth. Five more outs and New York would capture its fourth World Series championship in a row and its fifth in six years.

What happened next set both franchises on paths fraught with agony and ecstasy. Yankees closer Mariano Rivera blew the save and the game, giving Schilling's Diamondbacks their first title in the franchise's young history. Schilling, with Randy Johnson, was named co-Most Valuable Player of the World Series.

The rest is lore: Early playoff exits for the Yankees in 2002 and '03, Schilling's Thanksgiving courtship by Red Sox management in '03, his magnificent '04 American League Championship Series against New York, the '04 World Series, Clemens' multiple retirements, his Houston detour and his June '07 return to New York.

Meanwhile, fans will remember Clemens' heroic years in Boston, which became the stuff of melodrama after his falling out with the Red Sox. He was given a standing ovation in his last regular-season start at Fenway Park, on Aug. 31, 2003, when it was thought that he would retire. He was booed off the field on Oct. 11, 2003, after beating the Sox in Game 3 of a seven-game ALCS.

Still today, Clemens has pitched more games at Fenway Park than anywhere else.

"Roger's so wound up every time he pitches," said Yankees manager Joe Torre. "I'm sure this ballpark adds a little something to it."

Today, Schilling is 40 years old. Clemens, his mentor nearly two decades ago during an oft-recounted offseason workout in Houston, is 45. In middle age, Clemens has tested his physical limits. Mentally, he remains as tough and uncompromising as he was as a 21-year-old Red Sox rookie.

Torre draws another comparison.

"He's so remarkable," Torre said. "And in a lot of ways, he's like Pete Rose was. Pete continued to just have this urgency to do well, all the time. ... You see golfers when they get older; they can play two rounds concentrating, but maybe not four. But Pete Rose, I found remarkable, for every single game he'd try to be at the top of his game."

With pitchers, Torre concedes, "It's a little different. You have four or five days to get yourself ready to throw in one day.

"But I think just to maintain that intensity is pretty remarkable."

Pitching matchup
NYY: RHP Roger Clemens (6-6, 4.45 ERA)
Clemens faced the Red Sox five times during the 2003 season, his last in New York until this season. In 27 innings against Boston that year, Clemens had an 8.67 ERA; against the rest of the league, he had a 3.22 ERA. Clemens faced the Red Sox again on Aug. 29 at Yankee Stadium, allowing two hits, including a solo home run, in six innings.

BOS: RHP Curt Schilling (8-7, 3.93 ERA)
He's no longer Boston's ace -- that title belongs to Josh Beckett, who shut down the Yankees for seven innings on Saturday -- but Schilling has been the Red Sox's second-most-consistent starter since his return from shoulder rehabilitation on Aug. 6. He owns a 4.71 ERA in 122 1/3 career innings against the Yankees, numbers that don't count his playoff feats against the Bronx Bombers.

Player to watch
Yankees second baseman and Schilling slayer Robinson Cano, who wasn't on the squad that lost to Schilling in Game 6 of the 2004 ALCS, is 11-for-28 with three career homers against Schilling.

On the Internet
 MLB.TV
 Gameday Audio
•  Gameday
•  Official game notes

On television
• ESPN

On radio
• WCBS, 92.7 WQBU (Español)

Up next
• Monday: Orioles (Daniel Cabrera, 9-16, 5.37) at Yankees (Phil Hughes, 3-3, 4.91), 7:05 p.m. ET
• Tuesday: Orioles (Jon Leicester, 2-1, 6.32) at Yankees (Mike Mussina, 9-10, 5.28), 7:05 p.m. ET
• Wednesday: Orioles (Brian Burres, 6-5, 5.47) at Yankees (Andy Pettitte, 13-8, 3.89), 7:05 p.m. ET