ATLANTA -- After a visit to Dr. James Andrews on Tuesday, it appears Jonny Venters is not likely to rejoin the Braves' bullpen until the end of May, at the earliest. But there is still some uncertainty about what is causing the discomfort in his left elbow.
Andrews injected Venters with a platelet-rich plasma and prescribed four weeks of rest. The Braves are hopeful that the left-handed reliever will be healthy enough to begin a throwing program after resting his arm over the course of the next month.
The uncertainty surrounding Venters' condition is a product of the fact that MRI exams often produce inconclusive results for individuals who have already undergone Tommy John elbow reconstruction surgery. Andrews performed this surgical procedure on Venters in 2005.
"It's somewhat what we were expecting," general manager Frank Wren said. "But we wanted to make sure the surgeon who performed the surgery had a chance to look at him."
When Venters exited a Grapefruit League appearance against the Tigers last week, the early indications were that his elbow was structurally sound. There has been some thought that he is dealing with a bone chip or bone spur. But because an MRI exam was not performed, a precise diagnosis has not been provided.
While the Braves are saying it is too early to provide a timetable for Venters' return, there is certainly reason to believe he will need to spend most or all of May rebuilding his arm strength and preparing to pitch at the big league level again.
With Venters sidelined, Atlanta will provide more prominent roles to right-handed reliever Jordan Walden, who notched 32 saves for the Angels in 2011, and left-handed reliever Luis Avilan, who has impressed since making his Major League debut in July.
Like Venters, Avilan has displayed a plus fastball with impressive sinking action. The Venezuelan southpaw helped the Braves claim Monday's Opening Day win over the Phillies after entering in the fifth with two runners on and one out. Avilan retired the only two left-handed hitters he faced to preserve a one-run lead in the fifth inning, and then showed his versatility while retiring two right-handers in a scoreless sixth inning.
Venters has made 230 appearances since he made his Major League debut on April 17, 2010. The only pitcher with more appearances over the past three seasons is Cincinnati's Sean Marshall (231).
The heavy workload appeared to take a toll as Venters compiled a 4.45 ERA and surrendered six home runs in his first 40 appearances last year. In the 164 appearances Venters made during the 2010 and '11 seasons, he posted a 1.59 ERA, surrendered three home runs and held opponents to a .300 on-base percentage.
Venters was placed on the disabled list just before last year's All-Star break with a left elbow impingement. After resting for two weeks, he compiled a 1.71 ERA, did not allow a home run and limited opponents to a .292 on-base percentage in his final 26 appearances.
After coming to Spring Training feeling refreshed, Venters started to feel some elbow discomfort during the early portion of the Grapefruit League season. The Braves shut him down for 10 days after he issued four walks in one inning against the Cardinals on March 13.
Venters completed one inning in a Minor League game on March 23 in pain-free fashion. But he was forced to exit his March 27 appearance against the Tigers.
Mark Bowman is a reporter for MLB.com.