With the club's approval, the Yankees third baseman was seen by Dr. Peter Wehling for an Orthokine procedure during a Dec. 5-9 trip to Dusseldorf, general manager Brian Cashman said during a conference call with reporters.
Rodriguez's treatment was first reported by the New York Post. The three-time American League MVP heard about Wehling from Bryant, who has credited Orthokine with healing his right knee and left ankle to help him stay on the hardcourt for the Los Angeles Lakers.
"Kobe had maintained, according to Alex, that he felt significantly better because of it," Cashman said. "Alex was interested in pursuing it as long as the Yankees' medical staff was comfortable with it and vetted the process. He basically asked us to look into it."
Cashman said that Rodriguez, 36, reached out to the Yankees in November about Orthokine and that team physician Dr. Chris Ahmad headed the research, checking Wehling's background as well as contacting the Lakers' medical staff to learn more about their experience with Bryant.
Major League Baseball was also consulted to avoid the appearance that Rodriguez might be receiving impermissible treatment. Cashman said that the procedure is in compliance with the regulations of the World Anti-Doping Agency (WADA), and that Wehling's reputation led the Yankees to send Rodriguez overseas.
"Ultimately, Kobe Bryant went with this individual in Germany," Cashman said. "The more our doctor researched it, the more impressed he was with this guy's credentials and his reputation. Obviously, Alex is our biggest investment, so we agreed to allow him the extra miles to have it done in Germany."
Orthokine involves taking blood from the patient's arm vein, incubating it at 37 degrees Celsius and then spinning it in a centrifuge to isolate protective proteins. That solution is then injected into the afflicted area once or twice a week; in this case, Rodriguez's knee and shoulder.
The treatment is similar to the platelet rich plasma, or PRP, therapy that has been used by athletes -- including Rodriguez -- to treat joint pain and muscle injuries. Orthokine is said to have an anti-inflammatory, pain-reducing and cartilage-protecting effects, though its long-term viability is unknown.
"This is one of those therapies that tries to improve the life and the longevity," Will Carroll, an expert on sports injuries, told MLB Network. "Certainly, someone like Alex Rodriguez can't make the next step to something like a knee replacement. That's something the Yankees would rather see him do later in life."
Cashman characterized Rodriguez's shoulder ailment as minor. Rodriguez acknowledged during a June trip to Chicago that he was receiving treatment on his left shoulder, but called it "nothing out of the ordinary" at the time.
"I think this is more about maintaining health going forward, rather than having any problems at the present time," Cashman said.
Cashman said that Rodriguez is continuing offseason workouts and is expected to be ready for Spring Training. Hitting coach Kevin Long said that he plans to travel to Miami to begin working with Rodriguez next week.
"I think he's 100 percent right now, personally," Cashman said.
Rodriguez battled through what he called his most frustrating season in 2011, batting .276 with 16 home runs and 62 RBIs in 99 games.
"Hopefully going forward he'll be healthy for us again, because when he is healthy he's obviously one of the best players in the game," Cashman said. "Maybe this is an avenue that helps maintain his health.
"There's clearly a belief system that this type of treatment is beneficial, and if it is, it was time well spent. If it isn't, nothing ventured, nothing gained."
Rodriguez missed 38 games after being placed on the disabled list on July 14 -- retroactive to July 8 -- to undergo arthroscopic knee surgery to repair a torn right meniscus.
In Rodriguez's first game back from the DL on Aug. 21, he suffered a sprained left thumb while fielding a ground ball. He batted just .191 (13-for-68) after returning from the DL and was 2-for-18 (.111) in the AL Division Series loss to the Tigers.
"I've got a lot of work to do personally," Rodriguez said after the ALDS. "I've got to get my health back and I know exactly what I have to do to help this team get back to the top."