The Braves placed struggling reliever Jonny Venters on the 15-day disabled list with an "elbow impingement" on Thursday and recalled left-hander Luis Avilan from Triple-A Gwinnett, a day after Avilan was promoted from Double-A.

Venters has pitched as if injured for the past two months, but until the Braves announced he was going on the DL today there had been no mention of any injury at any point, including after Wednesday's night's 5-1 loss to the Cubs when the left-hander threw a seventh-inning wild pitch to let in a run and gave up a homer on the next pitch.

He has a 4.45 ERA in 40 appearances this season, after posting a 1.89 ERA in 164 appearances during his first two seasons in 2010-2011.

Venters has a 6.08 ERA and .343 opponents' batting average in 31 appearances since May 1, including a 9.45 ERA in 17 home games. The sinkerballer has allowed six homers in 21 innings over his past 28 appearances, after allowing only three homers in 182-1/3 innings over his previous 176 career appearances.

When asked after Wednesday's game how long the Braves could continue to use Venters in big situations given his recent performance, Gonzalez said, "Well, you've got to feel like you have confidence in the young man and you feel like you see some good outings [like Tuesday] night. You feel like you can get him over the hump, put him in situations where you think he's going to be successful, and then keep going forward.

"If we don't get him right — and I'm not even talking about last year right, just a good left-handed arm out of the bullpen — we're going to be up against it. We'll keep working. He's got a good frame of mind, and he's working with [pitching coach] Roger [McDowell]. And we'll keep going."

At about that same time, Avilan apparently was notified that Venters was injured and that Avilan had been promoted to the majors. He told other members of the Double-A Mississippi team and posted a few comments on Twitter saying how elated he was to be going to the majors for the first time.

One of his Tweets said, "I'm the happiest guy in the world ..!"

Avilan, 22, had just been promoted to Triple-A Gwinnett earlier Tuesday, and was promoted again without ever pitching for Gwinnett. He will be at Turner Field for Thursday night's series finale against the Cubs, as the Braves try to salvage a split of the four-game series and 10-game homestand. They've lost five of their past seven games and are 4-5 on the homestand.

Avilan had a 3.23 ERA in 16 games (12 starts) at Mississippi, with 55 strikeouts, 31 walks and 50 hits allowed in 61-1/3 innings. Left-handed batters hit just .189 with a .561 on-base-plus-slugging percentage against him this season.

The Dominican rookie has a 21-30 record and 3.42 ERA in 143 games (53 starts) over seven minor league seasons, with 375 strikeouts and 154 walks in 424 innings. Avilan signed with the Braves at 16 and didn't pitch above Class A until 2011. He spent two years in the Dominican Summer League and two more in the Braves' rookie leagues — Gulf Coast League in 2008 and Appalachian League (Danville) in 2009.

After going 4-8 with a 4.57 ERA in 36 games (13 starts) at Mississippi in 2011, he reduced his ERA by more than a run this season and raised his strikeout rate from 6.6 per nine innings to 8.1, although his strikeouts-to-walks ratio was not as good this season.

Venters has gone from arguably the best non-closer reliever in baseball the past two seasons to one of the worst statistically in 2012. Braves closer Craig Kimbrel has the the fewest baserunners allowed per nine innings (6.9) among National League relievers, while Venters (17.5) has the second-most among major league relievers.

Kimbrel has the second-fewest hits allowed per nine innings (3.90) among major league relievers, while Venters (11.41) has the third-most among NL relievers, just ahead of Livan Hernandez (11.53), who was released by the Braves and is now with Milwaukee.

Kimbrel leads NL relievers with a .126 opponents' average, while Venters' .313 is the third-worst in the NL, one spot ahead of Hernandez's .326.

Braves Kris Medlen and Venters are are tied with Colorado's Esmil Rogers for fifth-worst percentage of inherited runners stranded (53.3) among NL relievers. Each has allowed seven of 15 inherited runners to score, while the Braves' Eric O'Flaherty leads the league at 94.1 percent stranded, having allowed just one of 17 inherited runners to score.