DENVER -- Chris Nelson, the Rockies' Opening Day third baseman, was back in the lineup at third on Thursday after making most of his recent starts at second base. With converted catcher Jordan Pacheco winning the third-base job after spending time at Triple-A Colorado Springs to strengthen his fielding skills, and with Marco Scutaro playing shortstop while Troy Tulowitzki is on the disabled list, Nelson has gotten the lion's share of playing time at second.

"He's emerging," manager Jim Tracy said of Nelson. "The power capability that he shows to right-center field -- this guy can hit a ball out of any part of the ballpark. He was not as good a defensive baseball player at second base as he is right now. That is very, very encouraging.

"The strength of his throwing arm on a double-play turn, there's not too many baserunners that are going to outrun that arm strength. They're incapable of doing it. This guy has a bazooka."

Pacheco, meanwhile, has shown vast improvement in the field while exceeding expectations at the plate, hitting .306 through 49 games in his rookie campaign. Pacheco sat out Thursday due to a sore right quad, but is expected to be back in the lineup Friday.

"His defense was extremely challenged early in the season," Tracy said of Pacheco. "We know that. And the other team got some runs because of some balls that you would say [were] makeable plays. But he re-acclimated himself to being an infielder. You knew there was going to be some pitfalls, but you got to like what you've seen with some of the other stuff."

After starting the season as the third catcher and a backup first and third baseman, Pacheco was sent to Colorado Springs to get more consistent time at third base, enabling him to build the instincts necessary to field the position at the big league level and become an everyday presence in the Rockies' lineup.

"His first step to the right or to the left, we've actually seen the last three or four or five ballgames where he's starting to cover the 5/6 hole a little better," Tracy said. "He had a terrific crossover step [Wednesday night], dove and speared a ball, maintained himself to gather himself and make an accurate feed to second base to give Nellie a chance to return the throw to first base. Those are things that early on, he was trying to decide, 'Oh my gosh, the ball's coming to me, which base do I want to throw it to?' That's how far he's come."

De La Rosa not due back until at least September

DENVER -- Rockies starting pitcher Jorge De La Rosa's projected return to the rotation has been pushed back to September at the earliest, according to general manager Dan O'Dowd, who gave the timetable in a conference call with season-ticket holders Wednesday.

De La Rosa has been recovering from Tommy John surgery following a season-ending injury to his left elbow in May 2011. Though he was initially expected to return to the club before the All-Star break, De La Rosa has had setbacks in his recovery and is currently receiving Protein Rich Plasma (PRP) injections.

"You can take up to three," head athletic trainer Keith Dugger said. "We'll do the injections and do a diagnostic ultrasound after every injection, to see if there's new scarring or healing process going on. He's had two."

Following the most recent injection, which could be the last unless a third injection is deemed necessary, De La Rosa can expect two weeks without any baseball activity as he recovers from soreness associated with the acute inflammatory response to the injections. The injections help promote the development of scar tissue to aid in the healing process.

"My goal from Day 1, and it still is my goal, is to have him pitch this year," Dugger said. "Absolutely, it's realistic."

Tracy gives Cuddyer break from starting lineup

DENVER -- Rockies right fielder Michael Cuddyer earned a day off Thursday as he works through a fallow stretch at the plate.

Cuddyer entered Thursday hitting .256 on the season, with 11 homers (tied for second most on the club) and 47 RBIs (second on the club), but he had struggled of late, hitting .098 (4-for-41) over his last 10 games.

"The first few days in this series, it appears as though he's grinding really hard, and there's something that he's searching for, so we're going to give him the day and give him the opportunity to not mentally grind, and also have an arena to find whatever it is that seems to be missing," manager Jim Tracy said.

Cuddyer has been a solid addition to the Rockies' lineup, and along with Carlos Gonzalez, he has provided veteran leadership for a club missing cleanup hitter Troy Tulowitzki.

Tracy was optimistic that a day without the pressure Cuddyer puts on himself would do the outfielder some good.

"He's such a competitor, and he grinds," Tracy said. "He wants to make such a contribution to this club each and every day. We're doing him a service, and we're doing the ballclub a service, just by allowing him to get away from it for a day. Don't mentally grind through the nine innings, and take the opportunity to mentally relax a little bit. Go to the cage and sort some things out."

Rockies to aid Colorado wildfire-relief effort

DENVER -- On a pair of nights featuring fireworks at the ballpark, the Rockies will be pitching in to help in the efforts associated with fighting Colorado's record-breaking wildfires.

Hundreds of homes have already been lost, with tens of thousands of residents forced to evacuate in a fire season that is currently absorbing half of the nation's firefighting resources. President Barack Obama has scheduled a visit to Colorado Springs, Colo., on Friday to visit the Waldo Canyon Fire, which has caused the greatest loss of homes to date.

"We are all devastated by the wildfires currently burning in our state, and we are doing everything we can to help," Rockies owner and CEO Dick Monfort said Thursday. "Our thoughts and prayers go out to everyone affected by these fires."

Fans will be able to make cash, check or credit card donations at Coors Field on Friday and Saturday night, with the Rockies and Padres facing off both nights. Friday's game is at 6:10 p.m. MT, and Saturday's first pitch is at 5:15 p.m. Gates open two hours before game time both nights.

One hundred percent of all donations will go directly to Colorado's fire relief efforts, and the Rockies have pledged a significant donation as an organization, though they have not disclosed the amount.