The team said Rodriguez has a strained left quadriceps and won't be able to return this week in Texas, as had been planned. Instead, he will remain on the disabled list and go back to Tampa, Fla., "for rest and treatment," the Yankees said in a statement issued before their game against the Boston Red Sox on Sunday night.
"He's going to be out for a while," manager Joe Girardi said after the Yankees lost 8-7 in 11 innings. "So we'll just deal with it and continue to play."
Mike Napoli hit a three-run shot after the Red Sox fell behind early, then he ended the game with a solo shot with two outs in the 11th—ending the 4-hour, 46-minute game at 12:53 a.m. Monday.
Only a day before, it appeared A-Rod was on target to return from offseason hip surgery early this week. Now, it's unclear when he might be back.
"I haven't really talked to the doctors about it. You never know how quick a guy's going to heal," Girardi said. "Until they walk through that door and they're ready to play, I don't count on 'em. It's kind of like the trade rumors."
It's the latest blow to the depleted Yankees, missing several injured stars almost all season. Derek Jeter, Mark Teixeira and Curtis Granderson came back and quickly got hurt again. Rodriguez didn't even finish his rehab assignment.
Rodriguez and Girardi had said they were hoping the third baseman would be back for Tuesday night's game against the Rangers.
He was sent Sunday to New York-Presbyterian Hospital to be examined by team doctor Christopher Ahmad, and an MRI showed a Grade 1 strain—the least serious level. It's the same injury that landed Jeter on the 15-day DL after his one-game return from a broken ankle.
Jeter was injured July 11 and won't be back until late this month, at the earliest.
Before the quadriceps injury, the original plan was for Rodriguez to rejoin the Yankees on Monday in Texas. Girardi then told reporters at Fenway Park at about 5:50 p.m. on Sunday that Rodriguez might make his 2013 debut on Tuesday.
"I would be surprised if he played Monday. Tuesday's possible," Girardi said.
But at 7:37 p.m.—about a half-hour before first pitch—the Yankees sent reporters an email saying the nearly 38-year-old Rodriguez "will not be joining the team for its series in Texas."
Rodriguez had surgery on his left hip in January and hasn't played a major league game this season. His 20-day minor league rehab assignment expired on Sunday, and the Yankees had to activate him or leave him on the disabled list.
The team said it might petition Major League Baseball for another rehab assignment because of the new injury.
"I think we're all a little bit anxious to see how he looks physically and how he's moving," Girardi said before the results of the MRI were announced. "I've talked to people that have seen him and said he ran good yesterday. ... I am anxious to see. He hasn't played in a while and he's almost 38. You kind of want to see what you've got."
Rodriguez told reporters in Scranton, Pa., on Sunday that he expected to work out on Monday and be back in the lineup Tuesday. He wasn't sure if he would play third or DH upon his return, he said.
If Rodriguez can regain his MVP form—rather than the one that got him benched during the 2012 playoffs—his return would be a boost for a lineup that has been without most of its biggest stars.
Jeter went back on the disabled list Friday and has played only one big league game all season. Teixeira (wrist surgery), Granderson (broken pinkie), infielder Kevin Youkilis (back surgery) and catcher Francisco Cervelli (broken hand) are also out.
During the offseason, Rodriguez's name surfaced in an investigation of Biogenesis, an anti-aging clinic in Florida linked with the distribution of performance-enhancing drugs. He met with investigators from Major League Baseball earlier this month.