BOSTON -- The Yankees could soon add a trio of formidable reinforcements to their lineup for the postseason push, as Greg Bird, Starlin Castro and Matthew Holliday all have Minor League rehabilitation assignments underway.
Coming off right ankle surgery, Bird hit two homers for Triple-A Scranton/Wilkes-Barre against Durham on Friday, and he is 4-for-10 with three runs scored and four RBIs in three games with the Yanks' top farm affiliate. Castro (right hamstring strain) went 0-for-4 with a walk in that game, while Holliday (left lumbar strain) went 0-for-4 with a walk and an RBI groundout for Class A Advanced Tampa in a 7-6 loss to Fort Myers.
"They were all middle-of-the-order hitters when the season started, which is interesting," Yankees manager Joe Girardi said. "The good thing is, if you get them back and they're going well, our lineup becomes so much deeper with experience, which I think is important. You get a Starlin Castro and a Matt Holliday back with experience, I think that would be important to this club."
Though Bird was the first of those three to resume playing games, he would not necessarily be the first to be activated because he has been limited to just 60 at-bats this year, batting .100 (6-for-60) in the big leagues. He played 12 Minor League games on rehab in early June before being diagnosed with inflammation in the os trigonum of his right ankle.
"For Greg Bird, just because he hasn't played a lot in the last two years, it's hard to say how long it might take him to get going," Girardi said. "Sometimes I feel like young guys, though, in those situations, you can get going a little bit quicker than an older player."
Though Bird has said that he hopes to rejoin the Yankees next week, Girardi said that he is not expecting the first baseman to be ready for the series against the Tigers at Comerica Park from Tuesday through Thursday.
"That's not something I've heard, but again, sometimes things are based on need," Girardi said. "I want the kid to get some at-bats before we decide [if he's] ready. I don't want to rush him."
Castro was sidelined from June 27 through July 14 with a hamstring injury that forced him to miss the MLB All-Star Game presented by Mastercard, then played in just six games before aggravating the injury. Holliday reported that he tweaked his back in an Aug. 4 game at Cleveland; he batted just .136 (11-for-81) after returning from an earlier stint on the DL for a viral infection.

"You've got to see how Castro responds to playing every day, and how that hamstring responds, and Matty hasn't had a ton of at-bats either, especially the last couple of months," Girardi said. "When you bring them up, you want to make sure they're ready and they're productive."
Bombers bits
• Masahiro Tanaka threw a 37-pitch bullpen session on Friday at Fenway Park and said that he came away "very encouraged." Tanaka is on the 10-day DL with right shoulder inflammation but is expected to start one of the Yanks' upcoming games at Detroit.
• Outfielder Clint Frazier (left oblique strain) has not been cleared to resume swinging a bat. He will continue to rest.