For the Yankees catcher, who was broadsided by Boston's Eric Hinske on what was later deemed to be a "clean play" at the plate, such precautionary trips to hospitals have become commonplace.
Posada revealed that he has had the procedures, each requiring approximately 10 minutes, performed during each of the last three winters. The scans offer Posada peace of mind at a point when he can actually exhale and ponder the bruising he takes during the season -- a luxury neither he nor the October-contending Yankees can afford right now.
"You can't think about the negative, and you can't think about the stuff that could happen," Posada said. "You've just got to keep on hoping that everything is going to be fine and you can keep on playing the game.
"It could happen anywhere. It could happen walking down the street and you get hit by a car. You can't really worry about things that you can't control."
Posada believes that, through the course of his career, he has suffered "three or four" concussions. He was taken to Massachusetts General Hospital after Saturday's 10-1 loss at Fenway Park, and doctors took scans of the 36-year-old catcher's head and neck.
Though they proved negative and Posada said he slept well, the pounding of his headache quieting, Posada was offered designated-hitter duties, with backup Jose Molina assuming the catching role for Sunday's series finale.
Manager Joe Torre said he was concerned that Posada might have to deal with an assortment of foul tips off his mask, an inevitability that the manager would prefer to delay for another 24 hours.
"I need his bat in the lineup right now," Torre said. "We just decided to do the safe thing."
Torre said that he had been informed of Posada's medical status over dinner with the Yankees training staff on Saturday night. Somewhere along the line, Posada's regular trips for CT scans have also been topics of conversation, a personal decision that Torre said has proven wise.
"With what's gone on in football, talking about the cumulative effect of concussions, I think it's a great idea," Torre said. "It's a question no one can answer. I never thought about it until the football situation came up, the fact that there were so many. It's frightening."
Everyone's a comedian: Derek Jeter's immediate reaction concerning Posada's collision with Hinske displayed little concern. Standing in a tunnel outside the visitors' clubhouse at Fenway Park on Saturday, Jeter smirked and assured reporters, "He'll be all right. He's got a hard head."
Later, in a private conversation, Jeter apparently offered his good friend a little more heartfelt reaction.
"He makes fun of it, but he said he couldn't do what I'm doing," Posada said. "That's pretty encouraging."
Never forgotten: Doug Mientkiewicz found his way into the Yankees lineup on Sunday, taking over duties at first base after two days of questionable defensive play by Jason Giambi.
Mientkiewicz's season nearly ended here in June after a violent collision, when he was clobbered by Mike Lowell on a play at first base. Leaving the field on a stretcher, Mientkiewicz -- a member of the 2004 Red Sox who drew the fans' ire by briefly retaining possession of the final World Series out -- was given a standing ovation by the Fenway Park faithful.
They weren't quite as forgiving on Sunday, as Mientkiewicz took a verbal pounding from autograph seekers during batting practice.
"Give back the ball," Mientkiewicz said. "Yeah, I know. I've heard it before."
Torre said he selected Mientkiewicz over Giambi because Giambi's recent at-bats against Boston starter Curt Schilling have not been very good, not because of the hit-by-pitch Giambi suffered in Saturday's contest, apparent retaliation by Josh Beckett.
Rolling Thunder: Double-A Trenton secured the Eastern League championship on Saturday, posting a 10-5 victory at Akron to take the best-of-five series in four games.
The Yankees will recall two players from the Thunder, pitchers Tyler Clippard and Chase Wright, to join the club in New York. Both appeared and made starts for the Yankees earlier this season but are likely to be used only in emergency situations.
"They're champions," Torre said. "Maybe they'll rub off on our guys."
Bombers bits: Ross Ohlendorf, who made his second Major League appearance on Saturday, has made a quick impression on Torre. The Yankees manager likes Ohlendorf's power sinker and competitive attitude, calling him "intriguing." ... The Yankees plan to invite several Minor League prospects to New York to work out with the club and get a taste for Yankee Stadium, but the players will not dress or be added to the roster.
Coming up: Their nine-game road trip complete, the Yankees will return home on Monday to open a three-game series with the Orioles. Right-hander Phil Hughes (3-3, 4.91 ERA) will take on right-hander Daniel Cabrera (9-16, 5.37 ERA) on Monday, with first pitch scheduled for 7:05 p.m. on the YES Network.
Bryan Hoch is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.