DENVER -- Looking to add experience to the bullpen in the latter innings, the Rockies acquired right-hander Rafael Betancourt from the Indians on Thursday for Class A righty Connor Graham.

The acquisition of Betancourt, 34, who could fill the vacant primary setup role, was one of two bullpen-related moves on Thursday. The Rockies promoted their top pitching prospect, right-hander Jhoulys Chacin, from Double-A Tulsa. He will work in a middle-relief role.

The Rockies, who lead the National League Wild Card race by one game over the Giants and will face San Francisco in a three-game series at Coors Field starting on Friday night, have acknowledged looking for bullpen help.

That need grew on Wednesday, when right-hander Manuel Corpas announced that he will undergo arthroscopic surgery on Friday to remove bone chips from his throwing elbow.

The move gives manager Jim Tracy another late-innings weapon. Because of various injuries and slumps, the bullpen is operating without a primary setup man. Right-handers Juan Rincon and Matt Daley and the only left-hander, converted starter Franklin Morales, are pitching in the seventh and eighth depending upon the opposing hitter.

In the player-for-player deal, the Rockies will assume the remainder of Betancourt's $3.35 million salary for 2009. Betancourt also has a $5.4 million club option for '10, which the Indians said they would not exercise.

Betancourt went 1-2 with a 3.52 ERA in 29 appearances for the Indians. But he has held opponents to one run and two hits in four innings since July 9, when he was activated after spending six weeks on the disabled list with a strained right groin. The Rockies are hoping Betancourt can rekindle his effectiveness of 2007, when he was a key figure in helping the Indians to the American League Central title.

"He's throwing the ball very well -- not like he threw it in '07, but he's got a good changeup, a good slider, and he's been a good, durable eighth-inning guy for a number of years," Rockies general manager Dan O'Dowd said. "He's been in a lot of competitive, high-stress situations. You never know with bullpen guys, but hopefully he'll step right in and be a guy for us.

"I don't know that he'll ever have a season like '07, but he's better than we have in there right now. I think this will be a good environment for him."

Originally a shortstop in the Red Sox's system, Betancourt converted to the mound in 1997. His break came when he signed a Minor League contract with the Indians in 2003 and went 2-2 with a 2.13 ERA in 33 Major League games that season. He is 23-22 with a 3.25 ERA in 371 career appearances.

In 2007, Betancourt went 5-1 with a 1.47 ERA in 68 appearances while helping the Indians to the American League Central title. But last year, he went 3-4 with a 5.07 ERA in 69 games. Before making the deal, the Rockies scouted each of Betancourt's outings since returning from the DL and felt he could improve their bullpen.

"Every season, you never expect the team you're playing is out of the race or doesn't have any chance to do something," Betancourt said after learning of the trade following the Indians' 5-4 road victory over the Blue Jays on Thursday. "That's why I'm here, for a different reason. I like to win."

Graham, 23, the Rockies' fifth-round selection in the 2007 First-Year Player Draft, went 7-4 with a 3.14 ERA in 16 starts at Class A Modesto, and has held hitters to a .225 batting average -- after limiting batters to a .189 average last year while going 12-6 at Class A Asheville.

The Rockies will need to clear a roster spot for Betancourt once he reports.