The 36-year-old tore some tissue in his foot while rounding the bases after hitting a home run against Blue Jays left-hander Scott Downs on May 29. Giambi played one more game for the Yankees before being placed on the DL two days later.
Giambi completed his Minor League rehabilitation assignment on Sunday. He hit .227 (5-for-22) with nine walks and one home run over an nine-game rehab span that started in Class A Tampa and ended with Triple-A Scranton/Wilkes-Barre.
Giambi will need to prove he's ready to hit Major League pitching before he starts getting into the lineup every day. Yankees manager Joe Torre announced on Monday that Melky Cabrera would be his every day center fielder going forward, and with Hideki Matsui and Bobby Abreu already manning the corner outfield positions, Johnny Damon will be battling it out with Giambi for at-bats at DH.
"On a daily basis, we're going to go out and play the team we think has the best chance to win," Yankees manager Joe Torre said. "[Giambi's] certainly understanding of that."
"I'm not worried about it at all," Giambi said. "I'm just excited to get back and have the opportunity. I healed faster than everybody thought, and I'll do whatever the club needs."
A lot has changed since the last time Giambi played for New York. When Giambi suffered his injury on May 29, the Yankees found themselves eight games below .500 and 8 1/2 games out of the American League Wild Card. Since that time, Bombers have led the Major Leagues in wins, by going 41-21, and are now just a half game behind the Wild Card-leading Tigers.
"The guys are playing good baseball," Giambi said. "They definitely had the part of the schedule where they had to make a move. ... They didn't let up, which is great because you can't have those letdowns. They played great and got themselves back in the thick of the race."
Giambi spent the majority of his rehab at DH, but did play two games at first base. While he's not expected to be used there very often in New York, Giambi said he played the position pain free and will be able to take the field defensively whenever Torre wants.
"Everything worked out really well," Giambi said. "That was the big thing with Joe -- to help give him some options -- where maybe I can help the ball club."
To make room for Giambi on the active roster, the Yankees designated infielder Miguel Cairo for assignment. Cairo hit .252 with no home runs and 10 RBIs in 54 games for New York. The 33-year-old said even though the news didn't come as a complete surprise, it still hasn't been easy to deal with.
"It's hard," Cairo said. "It's a good group of guys, unbelievable coaches, good manager. This atmosphere -- for me, it was an honor to be here. Just to hang out with all these superstars, a bunch of good friends. A lot of times this is business. They had to make a move when Jason came back, and it was me."
Cairo's move also opened up a spot for 21-year-old prospect Joba Chamberlain to be added to the 40-man roster. Chamberlain had his contract purchased from Triple-A Scranton/Wilkes-Barre after New York optioned right-hander Brian Bruney to the Minors.
The Yankees have 10 days to trade, release, or re-assign Cairo to the Minor Leagues. Cairo said it was still too early for him to decide if he'd accept a Minor League assignment if he clears waivers.
"I need a couple of days to think about it," Cairo said. "Right now, I'm just trying to take it, and deal with it."
Gregor Chisholm is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.