"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."