Lowell, who will return to the Red Sox, needs radial collateral ligament surgery that will require 6-8 weeks to recover from. Sources said Lowell is scheduled to have the procedure done shortly after Christmas, and he should be ready to return to action by the first or second week of Spring Training.
Lowell's agent, Seth Levinson, could not be reached for comment on Saturday night.
The deal, which was agreed upon during the Winter Meetings in Indianapolis but was pending the passing of a physical, was to send Lowell to the Rangers in exchange for catching prospect Max Ramirez. In turn, Boston would also pay $9 million of Lowell's $12 million salary for next season.
But that will no longer be the case, and his role in Boston moving forward is in question.
"Well, I think the main thing for us now is just to help Mike get healthy," said Red Sox assistant general manager Ben Cherington while making an appearance on Sirius XM's MLB Home Plate on Sunday. "He's a good player, has been a good player and certainly a quality person. He's been a big part of our team for the last several years. And the trade, as we talked to Texas, it wasn't about not wanting Mike Lowell. It was about possibly making a move to get a player we liked back and give us a little bit of financial flexibility to do some other things."
Barring any moves, the Red Sox were expected to go with Casey Kotchman at first base for next season, with Kevin Youkilis switching to third. That can still happen, but if Lowell proves he's healthy, the Red Sox would also have two other options -- they can rekindle trade talks for Lowell, perhaps with the Rangers again, or they can have Lowell play third base.
"All the reports indicate that he should be 100 percent in Spring Training," Cherington told Sirius XM Radio. "Let him go out there and play, and he's either an important part of our team moving forward, a guy who obviously provides a good bat at third base so we have flexibility with Youk, who can move between third and first. Mike's an excellent hitter, an excellent hitter at Fenway Park, and so he'll be an important part of our team. And certainly if there's interest down the road, we can consider that."
In his fourth season in Boston in 2009, Lowell batted .290 with 17 homers and 75 RBIs in 119 games.
Lowell had surgery on his hip last offseason, and the right thumb was a problem for him during the end of 2009. He also strained ligaments in his left thumb in '08, which prompted him to go on the disabled list.
The Rangers were reportedly satisfied with the condition of Lowell's hip, and an examination of Ramirez's wrists by Boston also didn't seem to be an obstacle. The only question was Lowell's thumb, and after examinations on Saturday, the Rangers decided those questions were strong enough for them to back out of the deal.
Cherington said the injury wasn't initially considered serious, until Lowell, after taking some time off after the end of the season, picked up a bat again and still felt bothered by his right thumb, prompting him to get it checked out.
The injury is on the outside of the thumb, so Cherington said the club is "very optimistic that he'll be ready in Spring Training and ready to play on Opening Day."
The Red Sox were reportedly interested in signing third baseman Adrian Beltre, and rumors swirled recently about an interest in trading for Padres first baseman Adrian Gonzalez. Having Lowell on the active roster -- and not saving $3 million on his contract -- may affect those moves.
In Texas, the 12-year veteran was expected to serve as a designated hitter and play first base, while also spelling Michael Young at the hot corner. The Rangers, meanwhile, are still looking for a right-handed bat and have interest in Vladimir Guerrero and Jermaine Dye.
"I expect we'll still add to the club in a few spots," Rangers general manager Jon Daniels said. "We've been in regular contact with guys we're interested in and I like our options."
Lowell was examined by a hand specialist in Arizona on Friday, then the Rangers' medical staff on Saturday in Arlington. The Miami native injured his right thumb while taking batting practice during the final week of this past season. Lowell sat out the final weekend of the season, then played in the three-game American League Division Series, notching two singles in 10 at-bats while the Red Sox were swept by the Angels.
For his 12-year career, Lowell -- a four-time All-Star and Gold Glove Award winner in 2005 -- sports a .280 batting average with 218 home runs. He also owns two World Series rings, with the Marlins in '03 and the Red Sox in '07.
In Ramirez, the Red Sox would've received a right-handed-hitting catcher who was originally signed by the Braves as an undrafted free agent in 2002. The 25-year-old played in 76 games for the Rangers' Triple-A affiliate last season, batting .234 with five homers and 43 RBIs while battling wrist problems.
Ramirez, who appeared in 17 games for the Rangers in 2008, has a career .300 batting average with 69 home runs in six seasons in the Minors. He was possibly going to move to first base or DH.