On Thursday afternoon, he became the front-runner to be the starting first baseman for the New York Yankees when they open the season on Monday against, you guessed it, the Boston Red Sox.
"Not many people wear those rival uniforms within the same 48 hours," a slightly baffled-looking Overbay said in the Yankees' clubhouse Thursday. "I've got a lot of firsts; that, then a three-day contract and a one-day extension."
Hours after his release by the Red Sox, the Yankees scooped up Overbay as insurance at first base, having lost Mark Teixeira for eight to 10 weeks to a wrist injury and being less than overwhelmed by his potential replacements, Juan Rivera and Dan Johnson.
When the Yankees released Rivera on Thursday afternoon, the field basically fell apart in front of Overbay. Asked if he had any other options at first, manager Joe Girardi said, "Not right now, no."
Given general manager Brian Cashman's penchant for stockpiling cast-off talent from other teams, that can change in the next 48 hours. But while Cashman was quick to point out that Overbay had not officially made the team, even he had to admit, "Clearly, he's got an inside track."
What a short, strange trip it's been for Overbay, who was told on Tuesday he would get "a three-day audition," and then got that rarest of concessions from the Yankees -- an in-season contract extension -- even if it's only for one day.
"He's coming to D.C. with us," Cashman said, alluding to the Yankees' barnstorming game against the Nationals on Friday afternoon.
Said Girardi: "As of right now, we're going to continue to look at Overbay."
Obviously, the Yankees have already seen enough to convince them it was not worth their while to add Rivera to their 40-man roster, nor was it worth the $1.2 million they were obligated to pay him if he made it.
And they have seen enough to know that Overbay, a reliable defensive first baseman, can save them at least as many runs with his glove as Rivera could produce with his bat.
And for the offensively-challenged 2013 Yankees, "defense is key," as Girardi put it.
"I've never been in this situation," Overbay said. "It's kind of been a whirlwind, but I don't have anything else to do. I'll just enjoy it."
Overbay is a career .270 hitter who has averaged about 11 home runs and 48 RBIs a year over his 12 big-league seasons -- the numbers skewed downward by the past two seasons in which his stats nosedived while shuttling between three clubs.
His best season was 2006, when he hit .312 with 22 home runs and 92 RBIs for the Toronto Blue Jays. He has played in just three games this spring for the Yankees, twice as a late-inning replacement for Rivera and once as a starter, and collected three hits -- one a double -- in nine at-bats, hardly enough of a sample to make a responsible judgment.
At the same time, it may have impressed the Yankees that Overbay was able to perform that well knowing he had such a brief window in which to show them what he had left.
"It's tough, and I think that's why I was a little too aggressive on my first at-bat," he said, referring to an overswing Tuesday night that resulted in a shallow fly to center with a runner on third. The fly out became a double play when pinch runner Neil Medchill, a rookie, was thrown out at home trying to score.
Overbay rapped into another double play on Thursday but also doubled with two outs in the ninth, giving the Yankees one last chance to tie the game, which they did not. He also went 2-for-5 in his only start Wednesday night.
"They know what a good swing is," Overbay said. "That's a big part of it. That's why I wanted to get here as soon as possible, let them see me. They don't get to see me on a [regular] basis every day, so that's why I wanted to get here."
Overbay said he barely thought twice when his agent told him the Yankees had expressed an interest in him after his release.
"I felt like this opportunity was one of the better ones if not the best," he said. "I wanted to get it done and get up here as soon as possible. I was like, 'Let's just do it.'"
He drove the 2 1/2 hours from Ft. Myers to Tampa, leaving his wife, Sarah, their four kids, and all his clothes behind, and in his haste understandably did not bother to memorize the Yankees' travel schedule; when he heard they were playing a game against the Nationals on Friday, Overbay assumed the game was at their training camp in Viera, Fla.
When he learned Wednesday night that the game was actually in Washington D.C., that the team would be flying there immediately after Thursday's game and that he would be going along with them, Sarah Overbay was pressed into delivery service.
She drove the 2 1/2 hours to Tampa on Thursday morning to deliver her husband's clothes, drove back to Ft. Myers to retrieve her own stuff, and then was headed back to Tampa.
"She put in about nine hours of driving," Overbay said. "She's a keeper."
Right now, the Yankees feel the same way about Mr. Overbay.
"I'm just along for the ride to see what I can do," he said. "I'm just trying to be as professional as I can, take good at-bats and show them what I've got in a short amount of time."
But he wasn't taking any bows or accepting any congratulations.
"Not yet," Overbay said. "I've been around this game a long time and things can change real quick."
Ask Juan Rivera.