Takashi Saito

At least for the moment, it's safe to say that the Yankees' decision to sign Bartolo Colon to a minor league deal has paid off. Aside from a four-inning, five-run no-decision at the hands of the Rangers four days ago, Colon has pitched efficiently into the late innings in each of his four starts, his fastball is just a half-a-mph below his career average, and he's striking out batters at his best rate since 2000.

Of course it's early in the season, but MLBTR's Mike Axisa recently pointed out that according to a Fangraphs statistic that calculates a player's financial value based on how much teams have paid free agents for similar production, Colon is already worth more than double the $900K the Yankees are paying him.

What's to explain Colon's resurgence, at age 37 and after five years dominated by shoulder and elbow problems?  According to a story in the Dominican daily Diario Libre, the new life in Colon's arm could be partially attributable to two treatments of stem cells – or "células madre" as they're called in the Dominican Republic, where Colon had the procedures. The doctors, Sergio Guzman and Leonel Liriano, told the newspaper they had envisioned using the treatment on Pedro Martinez, but they also sent "an invitation" out to Colon, which he accepted in March 2010. (Pedro's invitation, the article says, is still open). Guzman was quick to insist, though, that when they took fatty tissue and bone marrow from Colon's hip and injected it into injured tissues in his rotator cuff and elsewhere in his right shoulder, they weren't doing anything revolutionary.

"We have not invented anything, nor have we done anything new. This is being done the world over," Guzman explained. "We received some training overseas to handle this type of things. Harvard University donated the centrifuges. This is no invention. What we do is take a little bit of bone marrow and we put it into an affected area."

Among major league pitchers, the bar for success with stem cell treatments is Takashi Saito, who received an injection of platelet-rich plasma in his pitching elbow in July of 2008, at age 38, in an attempt to avoid Tommy John surgery. Saito was closing for the Dodgers again by September, and was a largely reliable option for the Red Sox and Braves over the next two seasons.

The Yankees would be thrilled to have similar production from Colon, though they did not know the full story behind Colon's resurgence until recently. Yankees GM Brian Cashman told Serge F. Kovaleski of the New York Times that he had not known about the treatment when the team signed him. (Cashman has since learned about the procedure and informed MLB about it). In both Saito's and Colon's cases, the doctors insisted that age is precisely what made the pitcher a suitable patient.

"We did not want to do a trial on a young 23, 24 year old, because the effectiveness could be questioned due to his age," Guzman said. "We did it with a veteran, and we hope that Felix Sanchez and other Dominican athletes that have suffered injuries will also submit to this treatment so that they can prove what can be done with stem cells."

While Colon has had success on the international stage after his treatment, this new chapter in his career has yet to truly play out. But with no imminent threats to his role with the Yankees, he stands likely to be given the opportunity to prove himself as the first stem-cell success in a starting rotation.