But having an AL East third wheel in no way diminishes the fanfare between the two sworn nemeses, so strike up the band for another Boston-New York showdown.
Or as an insider, famous former shortstop Cal Ripken, said a couple of days ago on a conference call previewing Sunday's All-Star Selection Show on TBS:
"It still hinges upon Boston and New York. Tampa Bay is going to play a role in the Wild Card and in the division title down the stretch, but I think New York and Boston have too much experience and too much talent and those players will start stepping up. This is about gathering momentum and believing in yourself down the stretch."
So let the harvest begin.
They reconvene in Yankee Stadium for four holiday-weekend games, starting Thursday night. Much has changed since we last saw them together. Besides, that is, the fact they now both chase someone else.
For starters, introductions might be in order: They have gone 76 days between meetings, since the Red Sox's 7-5 victory in the Bronx on April 17 -- which at the time left Boston (10-7) a half-game up on Baltimore, with the 9-8 Yankees one length behind, the Rays really on no one's mind.
That's an awfully long lull in rivalry time. Things happen. People come and go.
Chien-Ming Wang and Phil Hughes, who started three of the five April games against Boston, are injured and out of the picture. Other April Yankees Morgan Ensberg and Shelley Duncan are just gone. The half dozen new faces include Darrell Rasner, who will get a start in the series, and Sir Sidney Ponson, who will not.
Oh ... and Joba Chamberlain has only gone from the eighth to the first inning, and on Sunday night will introduce Boston to extended exposure to his heat.
The Red Sox, thanks to a more stable pitching staff, haven't turned over as much. But they, too, have had goings -- Clay Buchholz, who lost two matchups with Wang in April, is back in Pawtucket -- and comings -- relievers Chris Smith and Craig Hansen, and Justin Masterson, the rookie right-hander who will match up with Mike Mussina late Saturday afternoon.
Both teams also have a big bat in traction, so to speak. Hideki Matsui, statistically still the Yankees' leading hitter with a .323 average, and David Ortiz, who has abused New York pitching for years, are both disabled.
Ortiz has been out a month with a torn tendon in his left wrist that has impaired his swing, but there's nothing holding back his mouth. Discussing his influence on a whimsical teammate, in fact, Big Papi came pretty close to echoing a certain former outspoken Bombers outfielder:
"I'm going to activate myself even if I'm hurt," Ortiz had said, "because I have the sword that can control the best of Manny Ramirez."
Reggie Jackson was the straw, David Ortiz has the foil. Choose your weapon.
Manny hasn't met a Yankees pitcher he doesn't like, judging by his monster numbers against them (55 homers and 160 RBIs in 194 games, of them a consistent 29 and 77 in 99 Yankee Stadium games).
About 220,000 fans who will pack Yankee Stadium will enjoy the next four days almost as much as will the Rays -- who concurrently will be hosting the Kansas City Royals, assured of each win gaining them ground on one of their division foes.
Ever think the Red Sox and Yankees would scoreboard watch while playing each other?
More new wrinkles, to underscore how the teams have evolved since their last face-to-face: Six of the eight hurlers scheduled to start in this series weren't part of the April action.
Set your rotations, and your watches (each of the four games will have a different starting time):
Thursday, Jon Lester vs. Andy Pettitte at 7:05 ET.
Friday, Josh Beckett vs. Rasner at 1:05 ET.
Saturday, Masterson vs. Mussina at 3:55 ET.
Sunday, Tim Wakefield vs. Chamberlain at 8:05 ET.
This will be not only Chamberlain's first start against Boston, but his first appearance of the season against the Sox. He wasn't used in the three-game Fenway Park series April 11-13, then missed the Yankee Stadium reunion while he was home tending to his hospitalized father.
Joba's steady evolution as a starter is peaking at the right time to heighten curiosity over how his coming-out against Boston will go.
Other story lines peaking our curiosity ...
Mark of a champion?
Neither has yet had it, frankly.
Boston? The Red Sox have lost 11 consecutive one-run decisions on the road, since edging Oakland in their stateside opener on April 1.
The Yanks? Have had eight different starters take turns in the Nos. 4-5 spots in the rotation -- and score a total of six wins in 34 starts; no strength in those numbers.
Will Mike Timlin be back in Boston's bullpen?
Jason Giambi hopes so; at the beginning of the season, when he couldn't hit anyone else, he clubbed two homers and a double in three at-bats against him.
The veteran right-hander has been rehabbing the left-knee tendinitis that has had him on the DL since June 21.
Definitely due back for Boston is Coco Crisp, the outfielder who gets his get-out-of-jail card on Thursday upon completion of the five-game suspension handed him for the fracas with Tampa Bay early last month.
Will the Yankees wilt in Boston heat?
The Red Sox invade with multiple scorching hitters. Dustin Pedroia is batting .500 (26-for-52) in his last dozen games. Mike Lowell, even after an 0-for-4 collar Tuesday night, has 17 hits in his last 36 at-bats. And J.D. Drew was crowned Mr. June after hitting more homers in the month (12) than any Boston player in a half-century.
The Yankees can't offer any matching momentum. Robinson Cano, apparently warming up for his usual July (he is a career .351 hitter in the month) has 12 hits in his last 26 at-bats. Otherwise, chill abounds, from Alex Rodriguez (2-for-17) to Melky Cabrera (0-for-19).
But, then, that's what Red Sox Nation and Yankees Universe will just have to do across the next four days. Chill out. Whatever the outcomes, the smell of spent fireworks will still be in the air when this series ends.
We'll still be too far away from the finish line to see it. The Red Sox and the Yankees will be only halfway through their 18-game seasonal series. Besides, the real enemy du jour will only be approaching: Next into The Stadium, the Rays.