"Bartolo Colon won the American League Cy Young Award in 2005, and less than five years later, it appeared his career was over after elbow ligament and rotator cuff problems.

In April 2010, however, Colon underwent a novel treatment in the Dominican Republic in which fat and bone-marrow stem cells were taken from him and then injected into his shoulder and elbow.

Colon, thought to be done, signed a minor-league deal with the Yankees last year, opened the season in the bullpen, and then joined the rotation the third week of April after an injury to Phil Hughes. He went 8-10 with a 4.00 ERA and was particularly effective in the first half, with a 3.20 ERA and 79 strikeouts in 15 games, 12 starts.

The controversial procedure worked.

"Incredible," Colon said through an interpreter on Saturday at Phoenix Municipal Stadium.

He acknowledged that he was nervous before the stem-cell injections, not knowing what to expect, and as for the results: "It is a surprise," he said. "I didn't realize I was going to come back and pitch so well."

When the A's signed the 38-year-old to a one-year, $2 million deal last month, they looked strictly at those results, rather than concerning themselves too much with the procedure. The long-term possibilities are unknown because there are so few examples. (Former journeyman pitcher C.J. Nitkowski, who turns 39 next month and last pitched in the majors in 2005, had stem-cell injections last summer and then played winter ball in the Dominican.)"