The slugger has a significant tear to the ulnar collateral ligament, one that he has been dealing with since 2003. But the nerve issue didn't crop up until the end of the '08 season, causing him numbness, tingling, weakness and pain.
"It was felt that the nerve was the source of his symptoms," said Dr. George Paletta, who performed the operation, "and that the ligament did not show any progression or change, and thus did not warrant reconstruction at this time."
At the end of the season, Pujols consulted with Paletta, the Cardinals team physician, and renowned specialist Dr. James Andrews. Following those discussions, the decision was made to perform the more minor operation.
"The last couple of weeks of the season he was complaining of some numbness and tingling in the fourth and fifth fingers, the pinkie and the ring fingers of the hand," Paletta said. "He was complaining of a little bit of weakness of his grip and he was complaining of some pain on the inside of his elbow in the forearm."
Since Pujols first sustained the injury, he has played with varying degrees of discomfort in his elbow. The pain was at its worst in 2007, and Pujols said at the start of '08 that if it became that severe again, he would have reconstructive surgery. However, that pain did not recur in '08, allowing him to avoid reconstruction for another year.
"My opinion," Paletta said, "is that we've managed this thing quite successfully since the initial injury, and this season was really one with no significant problems. So I'm still optimistic in fact that we can manage this thing without surgery for the remainder of his career."
Following the nerve transposition, the hope is that he will not miss any of the 2009 season. In its announcement of the operation, the club said that Pujols "will begin his rehabilitation this week and is expected to make his recovery by Spring Training."
More specifically, Paletta said that Pujols would likely be able to begin full baseball activities in approximately three months.
"I would not describe this as a big-deal procedure," he said.
Matthew Leach is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.