What if this Yankees legend had ended up on the Red Sox?

It all happened on Presidents' Day weekend in 2004, when the Yankees made one of the biggest blockbuster deals they had ever made, trading for Alex Rodriguez.

The deal was announced on Valentine’s Day, and Rodriguez would be introduced on Feb. 16 inside the Hall of Fame Club at the old Yankee Stadium. It was a trade that was supposed to change baseball history, for both the Yankees and the Red Sox.

And it did. Just not the way everybody thought at the time.

The Red Sox had tried to get Rodriguez away from the Rangers, but the deal eventually fell apart. The Yankees needed a third baseman because Aaron Boone -- the home run hero in Game 7 of the American League Championship Series against the Red Sox the previous October -- had torn up his knee in an offseason pickup basketball game.

The problem was solved when Rodriguez, one of the elite shortstops in the game, agreed to move to third because the Yankees happened to have an elite shortstop of their own in Derek Jeter. Just like that, Rodriguez, who had been No. 3 of the Rangers was No. 13 of the Yankees. No. 3 was kind of sort of taken with the Yanks, because Babe Ruth had worn it. He had been part of a pretty big deal himself once.

I was in Boston the weekend Rodriguez's deal was announced. Even four months after Boone’s home run off Tim Wakefield in the bottom of the 11th, there was still a very bad baseball hangover in that city, because of a moment that seemed to epitomize or maybe symbolize everything that had happened between the Yankees and Red Sox since Ruth.

I went over to the Red Sox team store across the street from Fenway Park and one of the young guys who worked there said, “At least we’ve still got Brady.”

He was talking about Tom Brady, who had quarterbacked the Patriots to a second Super Bowl title a couple of weeks before in Houston against the Carolina Panthers.

The general mood in Boston was that where baseball concerned -- my friend Mike Barnicle of MSNBC has always said that in Boston the Red Sox aren’t a matter of life and death, they’re more serious than that -- Rodriguez going to the Yankees was the end of everything. Somehow the Yanks, nicknamed the “Evil Empire” by Red Sox president Larry Lucchino, had become an even more Evil Empire in the eyes of Red Sox fans.

Only the Rodriguez trade wasn’t the end of everything for Red Sox Nation. It turned out to be the opposite in Boston. Because since that trade, the Red Sox have won four World Series this century, to the one the Yankees would win, in 2009, with Rodriguez on their team.

Changing their history, of course, would really begin when they came back from being down three games to none against the Yankees in the ALCS, six months after the Yanks essentially traded Alfonso Soriano for Rodriguez, with the Rangers agreeing to pay some of the money they owned Rodriguez, just to get out from under the massive 10-year, $252 million deal they’d given Rodriguez as a free agent a few years before.

Here is what Lucchino would say about that moment in his team’s history and Yankees history later to Boston’s WEEI.com:

“It was as vivid a reminder as one could have about the old cliché: The best trades are often the ones that never happen. It was also a bit of a reminder of the power and influence of the [Major League Baseball] Players Association [which wouldn't let Rodriguez take less money than he was making in Texas to play for the Red Sox]. I can’t say how it would have influenced our operating practices going forward. It would be purely hypothetical. I’m not going to try. ... [But] having won three in 10 years, we feel a sense of satisfaction and pride in what has developed in place of an A-Rod-led Red Sox.”

This was before the Red Sox won their fourth World Series since 2004 in '18, long after Rodriguez had stood in front of the cameras and microphones at Yankee Stadium and said, “At this point in my career I’m all about winning.”

In the middle of that 2004 season, Rodriguez would end up in a famous Fenway fight with Jason Varitek, on a day when the Red Sox came back to beat the Yankees. Bill Mueller hit a game-winning homer off Mariano Rivera that day. In October, in the bottom of the ninth of Game 4 of the ALCS, it would be Mueller who would tie the game with a single off Rivera and keep the greatest Red Sox season of them all alive.

It all began one Presidents' Day weekend, 18 years ago. Rodriguez to the Yankees and not the Red Sox. Supposed to be the end of everything in baseball in Boston. Turned out to be the beginning of the best baseball time the Red Sox have ever had, including when they still had Ruth. Now in Boston they think the Rodriguez trade, because it went down on a holiday weekend, ought to be some kind of baseball holiday. Theirs.