The left-hander had Tommy John surgery to reconstruct the ulnar collateral ligament in his elbow, the team said. The procedure was performed in Gulf Breeze, Fla., by Dr. James Andrews.
Andrews also performed the first Tommy John surgery on Venters when he was a minor leaguer in 2005.
The usual recovery time is around 12 months, but the period can be closer to 18 months for a pitcher undergoing a repeat operation. Under that scenario, Venters would miss two full seasons. Also, the chances of a full recovery are considered less promising for someone who needs the Tommy John procedure a second time, though some have returned to pitch effectively.
Serving as a setup man to closer Craig Kimbrel, Venters was one of Atlanta's most effective relievers over the last three seasons. He appeared in an NL-leading 85 games in 2011, going 6-2 with five saves and a 1.84 ERA. He was selected to the All-Star Game that year.
But Venters experienced occasional pain last season, limiting him to a career-low 58 2-3 innings, and he had more problems in spring training. He was shut down at the beginning of the season with what was described as a sprained left shoulder.
Hoping to avoid an extended stay on the disabled list, Venters underwent an injection and rested his arm for a month. But the pain returned when he began throwing off the mound, leading Andrews to conclude that Venters needed another Tommy John operation.