At the time, it seemed a large but reasonable price to pay for someone who arguably deserved the title of Best Pitcher on the Planet. When a pitcher of Johan Santana’s elite pedigree becomes available, a team could not help but be tempted to offer the farm in order to acquire him.

The proposals between the Twins and Red Sox took many shapes. Several times, Jon Lester heard his name mentioned as the headline of a package that would also feature Coco Crisp, Justin Masterson and Jed Lowrie.

Lester contemplated the names—the addition of the two-time Cy Young winner to the Red Sox rotation, a prospect-heavy package going to the Twins—and came to an immediate conclusion.

“It wasn’t a matter of if it’s going to happen,” recalled Lester. “It was one of those things where I heard the trade and I said, ‘Okay, I’m going to Minnesota.’”

Though the actual requests by the Twins and proposals by the Red Sox took many shapes, baseball officials confirm that the Twins sought a package that would include Lester, Masterson and Lowrie.

Ultimately, the Sox decided to hold onto their young talent and to resist the substantial temptation to acquire Santana. But what would have happened if the team had pulled the trigger to acquire a pitcher who went 16-7 with a 2.53 ERA in 234.1 innings for the Mets?

“We’re not heading to Anaheim (for the playoffs), I don’t think,” said Sox catcher Kevin Cash. “Johan’s awesome, but without those guys we’re not where we are.”

As much as the temptation exists to view the trade of Manny Ramirez for Jason Bay as the defining moment of the Red Sox season, several team members suggested that the non-deal of last winter was even more significant. If the Ramirez trade represented the phenomenon of addition by subtraction, the team’s decision not to acquire Santana represented addition by the refusal to subtract.

“Obviously, you would have gotten a Johan Santana, which would have been nice,” suggested teammate Sean Casey. “But Jon Lester might turn out to be the next Johan. I think he’s one of the top lefties in the game—no doubt about it. Masterson has an unbelievable upside. And Lowrie is going to be a good, solid big-league player. You would have lost a lot, and you would have had to pay (Santana) a lot, too.”

JON LESTER

Lester still seems surprised that the deal didn’t happen. The pitcher had been underwhelmed by his own big-league performance en route to an 11-2 record and 4.68 ERA through 2007, but club personnel felt differently.

As Minnesota drew out the trade talks about Santana, the outpouring of organizational support for Lester amplified. Pitching coach John Farrell proved especially adamant in making the case that the Sox should keep the pitcher.

Farrell, the former Indians director of player development, had been dazzled from afar by Lester in 2005, when the then-21-year-old was the Pitcher of the Year in the Double-A Eastern League.

“When he was in Portland in ’05, 21 years of age (throwing) 93-95, a left-hander, that’s as good as you’re going to find anywhere in the minor leagues,” said Farrell. “Those guys project to middle to upper (rotation) guys.”

Lester was surprised and flattered to learn of the sentiments offered by his pitching coach and manager Terry Francona about his bright future.

“It’s not often that you hear your manager and pitching coach going to bat for you with the front office like that—especially when they’re talking about getting a guy like Johan Santana,” said Lester. “Hell, I’d trade me for Johan Santana.”

Lester’s teammates disagree with such an assessment. It might seem like hyperbole to compare Lester—who has had a brilliant season—with Santana, who leads the majors in wins, ERA and strikeouts over the past five years.

Yet it is worth noting that, at the age of 24, Santana owned a career record of 23-12 with a 3.97 ERA. It was not until age 25 that he enjoyed a breakout during his first full season in a rotation.

Lester emerged as one of the top American League pitchers as a 24-year-old. He is now 27-8 with a 3.81 mark in his young career.

“What’s the difference between Johan and Lester right now?” mused Cash. “If you were to look at it one for one, I’m sure there are a lot of people in here who would want to have Lester.”

Lester blushed at the suggestion.

“That’s nice,” he said. “But I would still trade me for Johan Santana.”

MASTERSON AND LOWRIE

Yet Lester is only part of the reason why the non-trade has enjoyed enormous significance this year. The Sox may well have buckled under the weight of injuries and ineffectiveness if they had not preserved their depth.

The team had learned some unwanted lessons in previous seasons. Though they had remained relatively healthy en route to a 2007 title, the team had endured unpleasant scrambles for replacements in 2005 and 2006.

Those years, they shuttled players (names like catcher Javier Lopez and pitchers Mike Remlinger and Jason Johnson come to mind) in and out of the organization, often with predictably poor results.

This year, the team has faced a constant onslaught of injuries. Yet thanks to the versatility of Lowrie and Masterson, as well as the presence of both Jacoby Ellsbury and Crisp (other players mentioned frequently in trade rumors with the Twins), the team has been able to withstand the fact that 15 of its players have landed on the D.L. this year.

“Our organizational depth played a big part of getting in this year,” said G.M. Theo Epstein on the night that his team clinched a berth in the playoffs. “It’s always a proud day for the organization when you get in, but this year it was for the whoooole organization. A lot of good scouting and good development went into our survival this year.”

The team did not expect that the players who were brought up in connection with the Twins would necessarily have to play such a large role in the season. But the Sox were certainly aware that they would compromise their depth significantly if they made a deal for Santana.

“A big part of our calculus,” one team official said of the Santana talks, “was appreciating the value of depth.”

That emphasis became immensely important over the course of the year. The team unexpectedly needed rotation reinforcements when Curt Schilling and Bartolo Colon were rendered non-factors and Clay Buchholz failed to take possession of a rotation spot. Masterson was there.

The team needed to reinforce a bullpen that seemed thin through its inconsistencies. And so, Masterson was moved to relief.

Mike Lowell spent two separate spells on the disabled list. Julio Lugo missed the entire second half. Lowrie proved a capable replacement, helping to keep the left side of the infield steady when it would have been easy for it to become a glaring weakness.

“You see the teams in the playoffs—Anaheim, Tampa, us, they’re deep, deep organizations,” observed Sox infielder Alex Cora. “You lose one guy, and another guy comes up and plays. You don’t take a step back because someone else is playing.”

Masterson and Lowrie have both exceeded expectations about what they might be able to contribute. Masterson was never phased by his rapid ascent from Double-A to the majors. He went 4-3 with a 3.67 ERA as a starter, and has dominated while going 2-2 with a 2.36 mark as a reliever.

Lowrie offered a striking amount of production (39 RBIs in his first 58 games) before cooling off offensively over the last month. Yet even while he has slowed at the plate, he has remained a source of great stability in the field.

He has yet to commit an error at shortstop, and despite doubts about his range, most statistical measures indicate that he has gotten to as many balls as anyone in baseball since coming to the majors.

“I don’t think any of the guys whose names appeared in articles surrounding that trade, those players that have had some success for us this year, I don’t think we’re surprised by it,” said Sox Vice President of Personnel Ben Cherington. “But we’re certainly pleased.

“You never know until they get there and adjust to that environment. It’s nice that we were able to make a decision to hold those guys and have some of the kids give a return on that decision in the short-run.”

THIS YEAR AND BEYOND

Several years from now, it may be that the Sox lament the day when they did not trade for Santana. The perceptions about trades (and non-trades) change dramatically over time.

In 2006, it looked like the deal for Josh Beckett might prove a devastating one for the Sox. In 2007, Hanley Ramirez represented the necessary cost of a World Series win.

That deal offers a reminder that it would be a mistake to draw conclusions about the long-term ramifications of the Sox’ decision not to deal for Santana. But remarkably, it is hard to imagine that in 2008 the team would have reached the postseason if it had made the decision to acquire the most dominant pitcher of this decade.

“For us,” said Casey, “not making that trade was humungous.”

Alex Speier is a Senior Writer for WEEI.com.