"During spring training, it seemed inevitable that Twins pitching prospect Kyle Gibson would reach the majors this year. Now that's not happening before 2013, at the earliest.

Gibson will undergo Tommy John ligament replacement surgery on his right elbow, General Manager Bill Smith announced Thursday.

Dr. David Altcheck, the same doctor who handled closer Joe Nathan's Tommy John surgery in March 2010, will do Gibson's procedure Wednesday. The rehab program takes about one year, and the Twins don't expect Gibson to pitch competitively again until next fall, in their instructional league.

"We aren't going to do anything to try to shorten the process or anything that might affect Kyle Gibson's career," Smith said.

The 6-6 righthander was ranked the Twins' best prospect by Baseball America entering the season. He turns 24 Oct. 23, so he will be at least 25 by the time he reaches the majors."