He was talking, of course, about shortstop Derek Jeter, starting pitcher Andy Pettitte, catcher Jorge Posada and closer Mariano Rivera. The Core Four Set is exclusive to MLB.com and includes four 2009 World Series baseballs, each hand-signed by one of the active Yankees greats, and it went on sale Thursday and is selling briskly.The set is in a special four-ball display case engraved with each of their names and "The Core Four -- Yankees Legends 2009," all for $999.99. That may sound like a lot to some, but when you consider a Jeter 2009 World Series signed ball is going for $500, Rivera's for $300 and Pettitte's for $200, that pretty much means you are getting a fourth signed ball and the display free. "It crosses your mind, because every year you know guys can't come back," Jeter said after the parade, considering the inevitable possibility of a Core Four breakup at some point (Pettitte had a 2004-06 hiatus spent with the Astros, and Posada only played eight games in 1996, none in the postseason). "Some guys are retiring, some guys are moving on. You get a chance to reflect and look at everybody together as one group. We have a lot of memories together." Steiner Sports made that product, and here is another one that is especially timely: Nick Swisher and Johnny Damon signed World Series baseballs, along with a clean World Series ball in a triple-ball display case. It is timely because they just shared the same float during Friday's parade. Both played crucial roles in the Yankees' championship, which will be remembered by many largely for the "Damon Dash" double-steal in Game 4. Robinson Cano and Melky Cabrera is another popular combination up the middle for the Bronx Bombers, and they are paired in another signed triple-baseball set. There is something about this display case that makes you think: Walk-offs and pie in the face. As with the other three sets, these balls all come with Steiner Sports Certificates of Authenticity. Mounted Memories 27-Time World Series Replica Ticket Framed Collage. Another MLB.com exclusive, this piece features and 11-by-14 print that shows the 27 tickets from each World Series plus a blend of images from the Yankees' historic past. Each piece comes double-matted in team colors and is in a wood frame. The entire collective measures 18 by 21 inches. Meanwhile, the rush continues for the overall selection of Yankees commemorative merchandise that went on sale immediately after Cano threw over to Mark Teixeira at first to retire Shane Victorino for the final out. Click here for the champions department, and get started early on your holiday shopping. Official parade gear also is in demand now after what you just saw at Canyon of Heroes. Download the Game 6 clincher at the MLB.com area in the iTunes Store, and you also have a nice way to commemorate what just happened. Watch again as the Core Four all play a key role -- and it might just make you go for that four-ball set people are talking about. On Friday, the Core Four brought up the rear of the parade. Appropriately enough, Rivera was the closer of the parade, the final float, finishing it just as he finished up the 2009 season. "It was something special," Rivera said of the parade. "I never take it for granted. When I have the chance to do this, I thank God for that, because one day I won't be able to do that."
Mark Newman is enterprise editor of MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.