DENVER -- Chris Nelson underwent a successful procedure to shock his heart back into rhythm Tuesday at a local hospital, the Rockies announced.

Nelson was admitted to Sky Ridge Hospital on Monday after telling Rockies officials he "felt funny." Nelson was diagnosed with an irregular heartbeat, and after waiting most of Tuesday out to see if his heart would return to a regular rhythm on its own, doctors were forced to shock it.

The Rockies added Nelson, a 26-year-old infielder, to the 15-day disabled list, retroactive to July 16.

"Due to the fact that [his heart] was not able to go back into rhythm on its own, there's at least six or seven days of very limited activity he'll have," Rockies manager Jim Tracy said. "As a result, we had to put him on the disabled list."

To fill Nelson's place on the 25-man roster, DJ LeMahieu was recalled from Triple-A Colorado Springs.

In 58 games with the Rockies, Nelson, a 2004 first-round Draft pick out of Redan (Ga.) High School, has batted .256 with five home runs and 23 RBIs. He spent 15 days on the disabled list with left-wrist inflammation from May 16-31.

Herrera hospitalized with left-wrist infection

DENVER -- Jonathan Herrera became concerned about an infection on his left wrist early Tuesday morning and was admitted to a local hospital for treatment, the Rockies announced.

The infection came from Herrera's wrist watch, Rockies manager Jim Tracy said.

"He contracted some type of infection, I know they did a culture, but I don't know anything further than that," Tracy said. "He went to the hospital around 2 a.m. this morning; he was very, very concerned about it."

Herrera, a utility infielder, was added to the 15-day disabled list, retroactive to July 16.

"This [treatment and recovery period] will take several days, but we can't play that short-handedly for that long a period of time, so we had to place him on the disabled list," Tracy said.

To fill Herrera's spot on the the 25-man roster, the Rockies called up outfielder Andrew Brown from Colorado Springs.

Herrera, 27, spent 30 days on the disabled list with a strained right hamstring from May 23-June 22. In 45 games he has hit .246 with three home runs and six RBIs.

Chacin throws well in simulated game

DENVER -- Starting pitcher Jhoulys Chacin threw "very well" in a two-inning simulated game on Tuesday afternoon.

"He felt fine, was very free and easy," Rockies manager Jim Tracy said.

Chacin (right-shoulder inflammation) has been on the disabled list since May 2 after beginning the season 0-3 with a 7.30 ERA. He used his full complement of pitches on Tuesday, throwing 30 during the simulated game -- 15 per inning.

The next step for Chacin will be another simulated game on July 22 in Colorado Springs while the Rockies are in San Diego. Tracy expects the righty to add another inning, bumping the projected pitch total to 45.

"If he passes that test, we're getting closer to entertaining the thought of sending him out and getting him started," Tracy said.

It's possible Chacin will be limited to the hard stuff next week. In his five starts this year, he struggled commanding his fastball, issuing 15 walks in 24 2/3 innings. Of his 119 first pitches, 55 were called balls (46 percent).

"He was throwing his full complement today, but that's not to say they won't take something away temporarily because they want him to focus on his fastball command," Tracy said. "Forcing him to do that may necessitate him not using one of his pitches."

Defense key in Rox's Monday win over Pirates

DENVER -- The Rockies beat Pittsburgh Monday night, 5-4, thanks to a sacrifice fly by Dexter Fowler in the bottom of the ninth.

But it's likely they wouldn't have been in the position to win without some superb defensive plays.

Fowler made the highlight-reel one, leaping against the wall in center field to rob Rod Barajas of a likely home run in the third.

"Fowler is awesome back there," teammate Jordan Pacheco said. "Nothing can get by him."

Catcher Wilin Rosario picked off the speedy Andrew McCutchen at second base in the fourth inning, his 16th of the season.

Pacheco, the rookie third baseman, was the defensive star of the night though, notching four assists -- his second-most on the year -- and making two diving stops at the hot corner.

The first, a lunge to his left, prevented Pittsburgh's Clint Barmes from leading off the third inning with a single. "As a pitcher, people always say, 'Use your defense, let them do their job,'" starting pitcher Jeff Francis said. "They did that and more tonight."

Pacheco saved a double in the top of the sixth inning, diving to his right and corralling a ball he had no business getting to. His throw to first beat Josh Harrison by a foot.

"We saw two plays tonight from Pacheco that we haven't seen a lot of, which tells me the work [Rockies third-base coach Rich] Dauer is doing with him is paying off," manager Jim Tracy said after the game. "Progress is being made there, and I'm very pleased to see that."

Pacheco's efforts rubbed off on shortstop Josh Rutledge who, one hitter later, stabbed at a hard grounder to his left off the bat of McCutchen, then spun over his left shoulder and fired a throw off his back foot.

"I knew I had to get rid of it quick, so with a really fast runner the spin throw is about the only thing I can do," Rutledge said. "It was pretty exciting seeing [Pacheco] make that play -- it pumped me up. And the next one happened to come right to me."

After Pedro Alvarez hit a three-run homer in the top of the ninth off of Rex Brothers to tie the game, Barajas notched a one-out single. As if on cue, Pacheco turned the next grounder he saw -- from Barmes -- into an inning-ending 5-4-3 double play.

"Some days my defense is good, some days not so good," Pacheco said. "I've just got to be consistent, keep taking my grounders. I'll still have the balls I throw into the stands, but I'm limiting that."

Worth noting

• Andrew Brown, called up from Triple-A Colorado Springs to replace Jonathan Herrera, hit .317 in 86 games, with 20 homers and 84 RBIs -- second-most in the Minor Leagues.

"Those are pretty significant numbers," Rockies manager Jim Tracy said. "He's got a very interesting bat, and we're hopeful to find out more about the guy as we go on."

• Eric Young Jr. started the game at leadoff for the Rockies, while usual No. 1 hitter Dexter Fowler hit third. Fowler is the third No. 3 hitter the Rockies have used in the last three games (Carlos Gonzalez, Jordan Pacheco).