You could tell the pressure was getting to Derek Lowe.

Hours before he became the first pitcher ever to record three wins in clinching games in the same postseason, Lowe was pacing the Busch Stadium tunnel that connects the visitors’ dugout to the clubhouse, singing.

The song was “If you’re happy and you know it, clap your hands.” Repeat the second verse, same as the first. Over and over again, Lowe sang and, yes, he clapped along.

After he was done singing and clapping, and then done chatting with a couple hundred members of the press in the dugout, Lowe turned the bill of his cap around 180 degrees and went out and held the Cardinals’ lineup to zero runs on three hits in seven innings.

And so an 86-year-old story of repeated failure whose roots were bound in bad management and had nothing to do with ghosts or haunted memories reached its merciful end on a foggy night in St. Louis.

Two sloppy wins at Fenway Park by the Red Sox showed that the Cardinals did not have enough firepower to overcome Boston’s pitching and that the Cardinals’ pitching didn’t have the kind of arms needed to muzzle the Sox’ deep and disciplined lineup.

With the Red Sox all too aware of what can happen with home-field advantage and a three-game lead in a seven-game series – where have you gone,

Mariano Rivera? – they turned to their go-to October guy, Lowe.

Lowe certainly seemed the most unlikely of Red Sox pitchers to turn in such a masterful postseason performance, at least when October began. Banished to the bullpen after a disappointing year in the rotation, Lowe had been the enigma of the Red Sox’ otherwise solid rotation.

He ended the regular season with a whimper, winless in his last five starts, including a one-inning, seven-run implosion at Yankee Stadium on September 18 that temporarily sealed his reputation as a physically gifted pitcher who simply couldn’t be trusted from start to start.

Lowe’s 5.42 ERA this regular season was worse than it appeared, and his 14-12 record masked an average of 7.29 runs of support per nine innings. Yet lasting impressions sometimes count for more than prolonged performance when a player becomes a free agent. With his gem against the Yankees in Game 7 of the ALCS and World Series clinching win on Wednesday, Lowe could not possibly have left a better impression as he faces free agency.

Ditto Pedro Martinez, who put together a season – 16-9, 3.90 ERA, no missed starts, 227 strikeouts, 61 walks – that pales only in comparison to his own immortal standards. Like Lowe, Martinez went out with a bang, retiring 14 Cardinals in a row to end a seven-inning scoreless Game 3 start in his first ever World Series appearance.

Both Martinez and Lowe, as well as catcher Jason Varitek, are going to be free agents this fall, and how the Red Sox’ treat the trio in this hot-stove season will be fascinating. Never before has the Boston brass been in such a position of strength, but team owner John Henry said in St. Louis that the team will handle its free-agent negotiations no differently as World Series champions than they would as World Series runner-ups.

He would rather resign, said Henry, then rebuild from scratch.

“We’re going to have a very competitive team next year and we’ll do everything we can to win a championship next year,” said Henry. “We don’t do this as a hobby.”

Other than Martinez, Varitek, and Lowe, the remaining Red Sox core – Curt Schilling, closer Keith Foulke, right fielder Trot Nixon, left fielder Manny Ramirez, third baseman Bill Mueller, and DH David “Senor Octubre” Ortiz – is signed for next year.

The decision on Varitek may be the swiftest and easiest for the Red Sox brass to make. His relentless drive and smarts have elevated him to de facto captain status, and the coaching staff and pitchers are fiercely loyal to him.

Despite Varitek being represented by the fiercest bulldog agent of them all, Scott Boras, there is a swelling current of belief that the Red Sox will do all they can to sign him before another team can. Varitek will be expensive, though, especially with virtually no comparable free agent catchers coming on the market. You can expect the Red Sox to do what they must to keep him.

Martinez, with whom nothing is ever simple, is a completely different story. His pitching pedigree is summa cum laude, yet when some look into his future, they see a physical breakdown waiting to happen. Martinez turned 33 the day before he pitched his World Series gem, and his 33 regular-season starts in 2004 matched his career high. Not missing a start meant a tremendous amount to Martinez this season, as he aimed to prove that his physical problems from 1999 and 2001 are behind him and that he has at least three years left of great pitching.

The dilemma for the Red Sox lies in figuring out how much to pay for the 3.90 regular-season ERA Martinez posted, one that ballooned with an 0-4, 7.72 ERA home stretch. The $17.5 million Martinez made this season is an all-time record for a pitcher and Martinez is aware that he will not approach that again. Exceeding Schilling’s $12.75 million annual average salary is almost undoubtedly part of Martinez’s game plan, and he may want three years guaranteed.

The Red Sox are not sure they can commit for that long or go to the $13 million level with Martinez. On the other hand, they can’t look at the crop of Grade-A free agent pitchers – Carl Pavano or Matt Clement being the most notable – and know that they’re going to get a better option than Martinez.

It should not shock anyone if the Red Sox decide to cut their ties with Pedro as gracefully as they can, nor should anyone be surprised to see them make every effort to hammer out a good deal that ensures Martinez retires a Red Sox.

The Martinez decision remains a coin flip. Not so with Lowe.

Lowe delivered a huge dose of helium to his deflated free agent status with his magical October, and there are a lot of teams out there who believe they can replace his regular-season ennui with his postseason stuff. Don’t expect the Red Sox to be one of those teams. They have limited dollars to spend on pitching, and spending them on either Martinez or a premier alternative is their first priority.

Lowe is being shopped on Park Avenue again but the Red Sox are going to walk right by his storefront. He will be somewhere else next season. He’ll be happy and he’ll know it and he’ll be clapping his hands.

One can only wonder if the Red Sox will find themselves missing his song and dance act if they play deep into October again next season.

Mr. Silverman covers the Red Sox for the Boston Herald.