The Braves further strengthened the majors’ top-rated bullpen by trading for veteran left-hander Scott Downs from the Los Angles Angels in exchange for minor league reliever Cory Rasmus.

Downs 37 has a 1.84 ERA in 43 appearances this season with a .243 opponents’ average that includes a .196 average against left-handed hitters. He had a 1.24 ERA before his last appearance Thursday at Oakland where he gave up two runs and three hits including the first homer against him this season.

The veteran is owed a little less than $2 million of his $5 million salary and will be a free agent after the season.

The Braves wanted to get a proven lefty to take some of the load off standout rookie Luis Avilan the the Braves’ only lefty reliever since Jonny Venters and Eric O’Flaherty had elbow surgeries near the beginning of the season.

Bolstering the bullpen was a priority for the Braves before Wednesday’s non-waiver trade deadline and became more so after losing veteran starter Tim Hudson to a season-ending broken ankle Wednesday. With the trade price so high for the few front-line starters available on the trade market the Braves decided instead to make their bullpen even more formidable by adding at least one of the top relievers available.

Atlanta’s bullpen ERA is a majors-best 2.62 ahead of the Pirates (2.84) and Royals (2.95). Atlanta and Pittsburgh relievers are tied for lowest opponents’ average at .214.

Downs had a .183 opponents’ average during a stretch of 29 appearances through July 23. The Kentucky native’s 2.28 ERA since the beginning of the 2008 season ranks fourth among major league relievers (minimum 200 innings). He had a 1.24 ERA through 42 appearances this season before giving up three hits and two runs while recording one out in his last appearance Saturday at Oakland.

Rasmus 25 had a 1.72 ERA and 14 saves in 32 appearances for Triple-A Gwinnett this season with 48 strikeouts and 22 walks in 36-2/3 innings. He struggled in three major league appearances in his first two callups with the Braves this season allowing eight hits six earned runs four homers and three walks in 6-2/3 innings.