DENVER -- Chris Iannetta still might be the Rockies' catcher of the future, but his immediate future is in Triple-A Colorado Springs.

The Rockies demoted Iannetta after Sunday's game in Atlanta and promoted first-time big-league catcher Edwin Bellorin, who has hit a career-best .326 with nine homers and 45 RBIs this season for the Sky Sox.

Iannetta started the year with a chance to battle Yorvit Torrealba for the starting catcher's job. But Torrealba's breakout season and Iannetta's struggles -- a .179 average with two homers and 15 RBIs in 51 games -- have made it tough for him to even crack the lineup.

Manager Clint Hurdle decided when he pinch-hit for Iannetta in the seventh inning on Sunday that it was time for the rookie to get his at-bats somewhere else.

"It's more important for him now to go down and get at-bats, to give him a comfort zone just to go play games, play innings, make plays, put of at bats together, reestablish his confidence," Hurdle said. "He likes the things we've done, but to put him in play twice a week is a lot to ask, and [we're] in a pennant race."

Iannetta has been working on his swing and approach at the plate, but he had one hit in his last 32 at-bats and had not driven in a run since June 28.

"He was doing everything he can do," Hurdle said. "But there comes a time in athletics at this level when trying hard isn't enough."

The manager hopes a larger sample of at-bats will help Iannetta simplify his approach.

"I just think he overanalyzes," Hurdle said. "There's sometimes when he just needs to see and hit. And it doesn't need to be right down the middle. Sometimes the first strike is the best strike."

Bellorin got the news of his promotion on Sunday and said he had a sleepless night before arriving in Denver on Monday.

"It's exciting -- my first time in the big leagues," he said.

Bellorin, 25, spent six seasons in the Dodgers organization before signing a Minor League contract with the Rockies this past year. He said his work with Sky Sox hitting coach Carney Lansford with his hands and stance has helped him improved his hitting. Bellorin is hitting over .300 for the first time in his career.

"I've been seeing the ball well all year," he said. "I've been working out of the cage, before practice and after practice."

Bellorin will be expected to relieve fellow Venezuelan Torrealba, who has already played a career-high 72 games this season.

"I don't really know how games I've played so far," Torrealba said. "I don't know how many I've played before in the past. I just know right now I feel great."

Torrealba has lost 10 pounds this season by choice and said he's improved his speed and quickness behind the plate.

"Yorvit's capable of catching five games in a week," Hurdle said. "When it's five in a row, that would push him a little bit, because he plays with a lot of emotion. It's not like we needed a fresh body, we needed a productive body, and we're willing to give Edwin a chance."

An imperfect 10: The Rockies suffered their Major League-leading 10th walk-off defeat on Sunday in Atlanta. In fact, seven of the Rockies' last 16 road losses have been of the walk-off variety.

Home-field advantage: The Rockies have won a franchise-record eight straight series at home and are an MLB-best 18-5 at Coors Field since June 2. They have the third-best home record in the Majors (30-21).

The visiting Brewers have the best home record (39-20) and took two out of three from the Rockies three weeks ago in Milwaukee. The Brewers are the second-worst team on the road in the National League with a 21-32 record entering Monday's game.

Next up: Rockies rookie Jason Hirsh (4-7, 4.91 ERA) gets his second start since returning from the disabled list. Hirsh will go against Brewers lefty Chris Capuano (5-8, 4.86 ERA). Tuesday's game starts at 7:05 p.m. MT at Coors Field.